Chem/Phys Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

kilo

A

10^3 (k)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Mega

A

10^6 (M)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Giga

A

10^9 (G)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Tera

A

10^12 (T)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

hecto

A

10^2(h)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

deca

A

10^1 (da)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Deci

A

10^-1 (d)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

centi

A

10^-2 (c)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

milli

A

10^-3 (m)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Micro

A

10^-6 (μ)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

nano

A

10^-9 (n)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Pico

A

10^-12 (p)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

horizonal projectile motion=

A

cos

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

vf and vi formula with a and change in x

A

vf^2=vi^2+2achange in x

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

newton’s laws:

A
  1. objects at rest/motion will stay at rest/motion 2. F=ma 3. equal and opposite forces
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

4 fundamental forces

A
  1. gravity 2. electromagnetic force (dont need to know these) 3. strong nuclear force 4. weak nuclear force
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

center of mass

A

(x1m1+x2m2+x3m3)/(m1+m2+m3)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Fstatic (the maximum it can be, but if less than max then it is opp of force applied to move the object)

A

(coefficient of friction)(normal force)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

for gravity questions g=

A

m1m2/(r^2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

centripetal acceleration

A

v^2/r

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Hooke’s law: force needed to compress/stretch a string by x is

A

F=kx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

torque

A

F(d)sin() angle between force and lever arm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

work=

A

F(d)cos() angle between force and horizontal unit=joules=1 N(m)= (kgxm^2)/s^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

mechanical advantage of ramps vs pulley

A

less force, same work mechanical advantage= length of incline/height of incline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

power

A

work/time units: W=1 J/s kg⋅m2⋅s−3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

for projectile motion trig

A

angle formed with the x axis vx=vcos() vy=vsin()

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

velocity

A

area under a velocity v time graph is displacement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

acceleration

A

area under an acceleration v velocity graph is change in velocity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

kinematics equation missing acceleration

A

d=(vavg)t or d=((change in v)/2)t

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

kinematics equation missing displacement

A

vf=vi+at or (change in v)=at

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

kinematics equation missing final velocity

A

(change in x)=(vi)t+1/2at^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

kinematics equation missing time

A

vf^2=vi^2+2a(change in x)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

motion on an inclined plane

A

g perpendicular= gcos() g parallel=gsin()

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Kinetic Energy (KE)

A

1/2mv^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

energy is proportional to

A

mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

energy and ____ are two ways of talking about the same thing

A

work

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

gravitational potential energy

A

mass x gravity x height or mgh

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

potential energy of a spring

A

1/2kx^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

when choosing between using kinematics or conservation of energy, remember that

A

time is not used in energy calculations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

work

A

kinetic energy final-kinetic energy initial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

pressure

A

force/area units: 1 Pa or 1 N/m^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

work

A

pressure (change in volume) think of the scenario in which a piston is moving in and out of a cylinder, changing the volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

if a gas doing work to expand a balloon

A

then the gas has to cool because it is using energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Fahrenheit =

A

2(degrees Celsius) + 32

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

first law of thermodynamics

A
  1. Two bodies in thermal equilibrium are at the same T 1.Energy cannot be created or destroyed 2. The total entropy of a system must increase in every spontaneous reaction 3. The entropy of a pure, perfectly crystalline compound at absolute zero (0 K) is zero.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Change U=Q-W

A

first law of thermodynamics -the total energy change of a system is equal to the transfer of energy into the system via heat minus the work performed BY the system on its surroundings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

isolated system-

A

no exchange of energy or matter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

closed system-

A

no exchange of matter, only exchange of energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

open system

A

exchange of matter and energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

system gaining energy (heat and work)

A

heat into system, work by system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

system losing energy

A

heat out of system, work on system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

second law of thermodynamics

A

two ways of saying: 1. if two objects are in thermal contact but not in thermal equilibrium, then heat energy will flow from object with higher temp to object of lower temp 2. the entropy of an isolated system will increase over time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

heat

A

a mechanism of energy transfer and has unites of energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

temperature

A

static property proportional to kinetic energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

change in volume and change in length are proportional to change in temperature

A

change in length= (coefficient of thermal expansion constant specific to the substance)(length)(change in temperature)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

PV=

A

NRT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

zeroth law of thermodynamics

A

if one system (A) is in thermal equilibrium with two other systems (B and C), then systems B and C must also be in thermal equilibrium with eachother

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

lowest kelvin temp possible is

A

0 degrees (or absolute zero)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

isochoric

A

volume remains constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

isobaric

A

constant pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

isothermal

A

constant temp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

adiabatic

A

process where no heat exchange takes place

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

density =

A

mass/volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

remember mass and _____ are not the same

A

weight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

molarity

A

moles/liters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

density of water (need to memorize)

A

1000 kg/m^3 or 1 kg/L or 1 g/mL or 1 g/cm^3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

specific gravity

A

how dense something is compared to water (bc it is a proportion it does not have units)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

pressure=

A

force/area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

pressure on an object submerged in fluid=

A

(density of object)(g)(depth of submersion)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

absolute pressure

A

hydrostatic prerssure of submerged object + pressure of atmosphere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

the percentage of an object that will be submerged in water is proportional to its

A

specific gravity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

buoyant force is equal to

A

the weight of the fluid displaced by the object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

Pascal’s Principle

A

The rule that when force is applied to a confined fluid, the increase in pressure is transmitted equally to all parts of the fluid. watch video

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

higher velocity of a fluid

A

the more likely it is to become turbulent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

the flow rate and the pressure drop are proportional to each other

A

aka a large pressure drop will cause flow rate to increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

poiseulle’s law equation (describes flow of incompressible fluids through a cylinder)

A

know how variables relate to eachother, so if change one what the effect will be, memorize formula

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

Bernoulli’s Law

A

Law stating that pressure in a moving fluid is less when the fluid is moving faster. general ruled of ideal fluids: narrower tube->higher velocity narrower tube->lower pressure higher velocity->lower pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

venturi effect

A

narrower tube-> lower pressure (venturi effect), higher velocity higher velocity->lower pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

laminar flow

A

a smooth pattern of flow (opposite of turbulent)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

relationship between fluid velocity and cross-sectional area of the pipe through which the fluid is travelling

A

v1A1=v2A2 so fluid velocity and cross-sectional area are inversely proportional

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

properties of ideal fluids

A
  1. the fluid is incompressible 2. the fluid is not viscose 3. the fluid exhibits laminar flow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

increased flow speed resulting from being forced through a confined space results in

A

a zone of low pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

scalar quantities do not have

A

a direction (but vector quantities do have direction)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

E (magnitude of electric field)=

A

(kq)/r^2 or F/q The SI units of the electric field are newtons per coulomb (N/C), or volts per meter (V/m)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

Work (in an electric field)

A

W=(kQq)/r

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

potential energy of a chrarge

A

(kQq)/r -same as work

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

V, electric potential

A

(kQ)/r

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

Conductivity

A

A material’s ability to allow heat to flow (sigma)(area/length) -sigma is a constant that is the inverse of p

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

Resistivity

A

A material’s opposition to the flow of electric current. p(length/area) -p is a constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

dimagnetic

A

no unpaired electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

paramagnetic

A

Atom or substance containing unpaired electrons and is consequently attracted by a magnetic field

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

magnetic fields cannot be blocked

A

but, it can be rerouted with a material that conducts better than the materials around it, ie copper

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

electric field lines are drawn

A

from positive to neg charges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

an insulator does not have free electrons, but when a charged object is brought near it…

A

polarization does occur at an atomic level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

electric potential energy=

A

electric potential (charge)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q

electric potential=

A

k(Q/r)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q

1atm

A

ERROR!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

direction a current moves is

A

opposite that of the actual flow of electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
99
Q

voltage

A

(current)(resistance) V=IR The unit is Volt (V) which is also equal to Joule per Coulomb (J/C) The SI unit of electric current is the ampere The unit of resistance is the ohm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
100
Q

power=

A

current x voltage P=IV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
101
Q

Kirchoffs laws

A
  1. In accordance with the conservation of electric charge, the sum of currents entering a junction must equal the sum of currents exiting the junction 2. The sum of the voltage sources in a circuit loop is equal to the sum of voltage drops along that loop.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
102
Q

Resistors in parallel

A

1/R=1/R₁+1/R₂+1/R₃+…

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
103
Q

Resistors in series

A

R=R₁+R₂+R₃+…

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
104
Q

C (capacitance)

A

Q/V charge/voltage which means there are two ways to increase the charge in a capacitor 1. to increase the voltage, because a greater potential difference will drive the accumulation of more charge 2. to increase the capacitance, which is a measure of how well the capacitor itself, as a device, can store charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
105
Q

Capacitor

A

a device used to store an electric charge, consisting of two parallel plates takeaway for MCAT C (capacitance) =(constant)(A/d) (assumption is that this all occurs in a vacuum-but if there is something between the plates then multiply by the ratio of the constant for the substance/constant for vacuum) aka increasing the area of the plates and bringing them closer together will increase the capacitance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
106
Q

electric field arrow lines go from

A

positive to negative charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
107
Q

E (strength of an electric field)=

A

V/d (voltage difference/distance between the plates) *can only use this formula with uniform electric fields

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
108
Q

potential energy from a capacitor

A

PE=1/2CV^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
109
Q

Capacitors in Series

A

1/C=1/C₁+1/C₂+…

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
110
Q

Capacitors in Parallel

A

C=C₁+C₂+C₃+…

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
111
Q

magnetic fields only affect ______ charges

A

moving (unlike electric fields)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
112
Q

magnetic field generated by current moving through a wire

A

B=(constant)(current)/(2)(pi)(distance from the wire) B=(mu)(I)/(2)(pi)(r)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
113
Q

right hand rule for current-carrying wires

A

place thumb in direction of the current running through the wire (I), the direction of the magnetic field follows the pattern in which your fingers curve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
114
Q

force exerted by a magnetic field on a moving particle=

A

F= qvBsin() v=velocity q=charge ()=angle of the velocity of the particle to the magnetic field (force will be maximized when the motion is perpendicular) -applied to positive particles only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
115
Q

force exerted by a magnetic field on a current-carrying wire=

A

F=(current)(length)(strength of magnetic force)sin()

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
116
Q

Lorentz force

A

sum of the electrostatic and magnetic forces acting on a body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
117
Q

capacitance _______ as the distance between parallel plates decreases

A

increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
118
Q

When a dielectric material is introduced between the plates of a parallel-plate capacitor and completely fills the space, the capacitance

A

increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
119
Q

periodic motion

A

any motion that repeats in a regular cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
120
Q

potential energy for periodic motion

A

pendulum: mgh mass on an ideal spring: 1/2kx^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
121
Q

Hooke’s Law

A

F=-kx (restoring force)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
122
Q

Period of a Spring

A

Ts (period of a spring) = 2π√(m/k)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
123
Q

Period of a pendulum

A

Tp=2π√l/g

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
124
Q

large value of T (period) means a ______ frequency

A

low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
125
Q

Velocity of a wave

A

v = fλ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
126
Q

The speed of sound depends on

A

the compresibility (represented by the bulk modulus variable) travels slowest through gases bc they are the most compressible travels fastest through rigid, incompressible solids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
127
Q

Higher amplitude means

A

more energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
128
Q

in a standing wave the points of zero displacement are called _____ and the points of maximum displacement are referred to as _______

A

zero displacement=nodes maximum displacement=antinodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
129
Q

fundamental frequency

A

first harmonic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
130
Q

standing wave on a pipe vs standing wave on a taught string

A

pipe: ends on an antinode on one end and node on the other end taught string: ends on a node at both ends

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
131
Q

standing wave in a pipe

A

can only work for odd values of n

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
132
Q

speed of sound in air

A

343 m/s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
133
Q

Intensity of a wave

A

power/area (W/m^2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
134
Q

period and frequency are

A

inversely related

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
135
Q

Critical damping

A

the condition in which the damping of an oscillator causes it to return as quickly as possible to its equilibrium position (rest position)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
136
Q

Underdamping

A

damping in a system that experiences a small resistive force, so that the system oscillates with decreasing amplitude, slowly decreases to zero

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
137
Q

Overdamping

A

Heavy damping such that the system takes longer to return to equilibrium than a critically damped system, but returns to rest faster than underdamping

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
138
Q

viscous damping

A

is caused by such energy losses as occur in liquid lubrication between moving parts or in a fluid forced through a small opening

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
139
Q

beat frequency

A

f=|f₁-f₂| beats are caused by the interference of two waves at the same point in space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
140
Q

wave-particle duality

A

light can behave as both a wave and a particle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
141
Q

light is an

A

electromagnetic wave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
142
Q

speed of light (c)

A

3.00 x 10^8 m/s (fastest speed possible for all forms of conventional matter in the universe) all electromagnetic waves travel at the speed of light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
143
Q

Velocity of a wave

A

v = fλ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
144
Q

Energy of a wave

A

hf (h is planck’s constant) or hc/wavelength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
145
Q

high energy waves

A

high frequency, short wavelength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
146
Q

low energy waves

A

low frequency, long wavelength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
147
Q

spectrometer

A

generates a spectrum, used to determine the degree to which a substance, often in solution, absorbs different wavelengths of light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
148
Q

apparent color of an object

A

is caused by the wavelengths of light that dont absorb, aka an absorbance peak for a wavelength means that the substance will NOT appear to be that color

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
149
Q

reflection and refraction

A

both occur when the wave encounters a different medium than the on it is travelling in, diffraction=changes path, reflection=bounces off the new medium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
150
Q

Circumference of a circle

A

2πr

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
151
Q

Area of a circle

A

A=πr²

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
152
Q

SI base units

A

mass-kg, length-m, time-s, temp-K, amount of substance-mol, electrical current- A (ampere), luminous intensity - candela (cd)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
153
Q

scalar quantity

A

A quantity in physics, such as mass, volume, distance, speed and time, that can be completely specified by its magnitude, and has no direction. Distance, along with speed, is a scalar quantity, meaning that it measures only magnitude and not direction. Since the car continues to move throughout the process, distance is constantly increasing and is never negative.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
154
Q

when you take the square root of a decimal

A

it becomes a slightly larger decimal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
155
Q

mechanical energy

A

KE + PE is lost/not conserved when there is friction or air resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
156
Q

conservative force

A

A force, such as gravity, that performs work over a distance that is independent of the path taken. Gravity and the spring force are classic examples of conservative forces, or forces that do work that does not depend on the path taken. Conservative forces can also be thought of as those that act in situations where mechanical energy is conserved.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
157
Q

nonconservative forces

A

Forces that its work depends on the path. Eg: friction. Both air resistance and friction are nonconservative forces. If they are present during a scenario, mechanical energy will not be conserved.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
158
Q

One joule is equivalent to

A

one N∙m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
159
Q

one newton is the same as one ____

A

(kg∙m)/s^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
160
Q

Watts are the unit for….. and are equivalent to…..

A

power (kg∙m2)/s3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
161
Q

efficiency

A

(useful work) / (energy in)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
162
Q

laws of thermodynamics

A

The first law, also known as Law of Conservation of Energy, states that energy cannot be created or destroyed in an isolated system. The second law of thermodynamics states that the entropy of any isolated system always increases. The third law of thermodynamics states that the entropy of a system approaches a constant value as the temperature approaches absolute zero

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
163
Q

work (dealing with pressure)=

A

PΔV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
164
Q

A hoop and a sphere, each of mass M, are rolled down a frictionless ramp. At the bottom of the ramp, which object will have the greater translational velocity, and why?

A

An object’s moment of inertia contributes to its rotational kinetic energy. Since a higher moment of inertia correlates to a higher rotational KE, it also means that translational KE must be lower, as the sum of these two values must equal the potential energy at the top of the incline. For the sphere, more of its mass is concentrated towards the center than for the hoop. As a result, the sphere’s moment of inertia will be lower.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
165
Q

If a gas is expanding in a container, then ____________.

A

it is performing work on a container -it also loses heat because it is performing work, so it gets colder even though it gets bigger (when a gas is compressed, work is being done on it)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
166
Q

work-energy theorem

A

whenever work is done, energy changes aka work and energy are the same, work done=energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
167
Q

adabiatic

A

no heat or matter is added to the system/transferred

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
168
Q

Isobaric

A

constant pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
169
Q

isothermic

A

constant temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
170
Q

isochoric

A

constant volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
171
Q

Zeroth Law of Thermodynamics

A

If two thermodynamic systems are each in thermal equilibrium with a third, then they are in thermal equilibrium with each other.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
172
Q

First law of thermodynamics

A

Energy can neither be created not destroyed but it may be converted from one form to another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
173
Q

second law of thermodynamics

A

Every energy transfer or transformation increases the entropy of the universe.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
174
Q

Third Law of Thermodynamics

A

No system can reach absolute zero, so can never have anything below 0 degrees kelvin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
175
Q

Newton’s First Law

A

An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
176
Q

Newton’s Second Law

A

F=ma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
177
Q

Newton’s Third Law

A

For every action there is an equal and opposite reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
178
Q

Watts (units of power)

A

Joules/second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
179
Q

frequency of oscillation

A

f = 1/2π [√(k/m)]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
180
Q

Period of oscillation

A

inverse of frequency of oscillation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
181
Q

Convex v Concave meniscus

A

concave-when interacts with the walls of the container more strongly than it does with itself convex- when it interacts with itself more strongly than it does with the container

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
182
Q

scalar quantity

A

a quantity that can be described by magnitude only and has no direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
183
Q

units for electric potential

A

Volts or J/C (joules/coulomb)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
184
Q

units for electric field

A

N/C or V/m

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
185
Q

charge has units of

A

coulombs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
186
Q

electrostatic force has units of

A

newtons (like all forces)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
187
Q

Period of a pendulum

A

T=2π√l/g

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
188
Q

elastic potential energy of a spring

A

U = ½ kx^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
189
Q

1 atm is equal to

A

101,500 Pa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
190
Q

how do voltage and current go through parallel resistors

A

Voltage drops across parallel branches of a circuit are always identical; this idea forms the basis for Kirchoff’s second law. However, if the resistance values of the resistors are not equal, different amounts of current will pass through them. Specifically, more current will travel through the branch of lower resistance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
191
Q

of molecules in a mol

A

6 × 10^23 molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
192
Q

charge of an ion

A

1.6 × 10-19 C/ion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
193
Q

Capacitance

A

the ability of a conductor to store energy in the form of electrically separated charges C = εA/d

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
194
Q

a particle must have what to experience the effect of a magnetic field

A

it is evident that a particle must possess both velocity and a charge (whether positive or negative) to be affected by a magnetic field F=qvB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
195
Q

Lentz’s Law

A

Direction of the induced current is such that the induced magnetic field always opposes the change ex. This law, which brings to mind conservation of energy and even Le Châtelier’s principle, states that a change to a magnetic field will always generate a current that counteracts that change. Here, the external field is becoming stronger, or more heavily positioned out of the page. To resist this change, it will induce a current that promotes a field pointing the opposite direction, into the page. The right-hand rule tells us that this current must travel clockwise.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
196
Q

right hand rule for magnetic force

A

this is for positive charge, so if negative then flip

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
197
Q

what does not change when a wave goes from one media to another (and the two media have different densities)

A

frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
198
Q

the decible scale is a logarithmic scale in which each 10 decibel interval, or a factor of 10, thus a 40 dB difference represents a _______ difference in intensity

A

10^4 or 10000

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
199
Q

total internal reflection occurs only when traveling from a material with a _______ refractive index to a material with a ________ refractive index

A

higher, lower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
200
Q

convex mirrors have _____ focal lengths

A

negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
201
Q

convex mirrors always form ______ images

A

virtual

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
202
Q

Magnification equation

A

m = -i/o (negative because the image is inverted)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
203
Q

radius of curvature is equal to

A

twice the focal length

204
Q

photoelectric effect

A

The emission of electrons from a metal when light shines on the metal

205
Q

when a uniform magnetic field is used to accelerate particles (this is used in mass spec) then what can be assumed…

A

-the particles are charged -the particles are moving at a constant velocity -the particles have the same velocity

206
Q

strong nuclear force

A

the attractive force that binds protons and neutrons together in the nucleus

207
Q

bulk modulus

A

numerical constant that describes the elastic properties of a solid or fluid

208
Q

velocity of a sound wave through a medium

A

v = √B/ρ where B = bulk modulus and ρ = density When the bulk moduli of several media are equal, sound will travel the slowest through the material with the highest density.

209
Q

relationship between intensity and decibels of sound

A

dB = 10 log (I/Iinitial) I=intensity

210
Q

doppler equation

A

f’ = f (vsound ∓ vreceiver / vsound ∓ vsource). If the objects are moving closer together overall, the perceived frequency of sound should increase

211
Q

transverse v oscillating wave

A

longitudinal wave-This wave’s oscillation is forward-and-backwards in amplitude, while its overall direction of propagation is forward. Because the amplitude of oscillation is parallel to the direction of the wave’s motion, it is a longitudinal wave. ex slinky wave moving left to right if held straight perpendicularly A transverse wave-has an amplitude perpendicular to its overall direction of propagation. ex exercise ropes

212
Q

c=

A

lamda(f)

213
Q

Energy of a wave

A

hf

214
Q

in a double slit when looking at the light bands of constructive interference, the bands must be

A

bright region on the optical screen must result from constructive interference. This tells you that the two waves involved must be completely in phase, or differ by exact multiples of a wavelength

215
Q

Which changes are experienced by visible light as it moves from Medium 1 (n = 1.16) to Medium 2 (n = 1.68)?

A

Wavelength decreases while frequency remains constant. light rays are moving from a material with a low index of refraction to one with a relatively high one. According to the equation n = c / v (which can be rearranged to v = c / n), the light will slow down during this transition. From here, it is helpful to remember this relationship: velocity = λf. Since the velocity of this light is decreasing, the product of wavelength and frequency must decrease in a corresponding manner. Furthermore, the frequency of light does not change when that light transitions between media. Thus, it must be wavelength that drops to yield the predicted decrease in speed.

216
Q

When adding chemical reactions, the associated equilibrium constants can be

A

multiplied together to give the equilibrium constant for the overall reaction.

217
Q

SDS-PAGE-acts like a _____ cell, and negatively charged proteins move towards the ___________

A

electrolytic, positive anode SDS-PAGE uses a detergent (SDS) to make all proteins negatively charged. We should know for test day that electrophoresis requires an external power source, indicating that it acts like an electrolytic cell. This means the anode will be positive (higher potential), and the cathode will be negative (lower potential). Thus, the proteins will migrate towards the positive anode.

218
Q

electrolytic cell v galvanic/voltaic cell

A

https://www.khanacademy.org/science/chemistry/oxidation-reduction/electrolytic-cell/v/introduction-to-electrolysis For both: matter is added to the side where reduction is occurring electrolytic- REDCAT cathode (-) cell electric potential is negative (not spontaneous) galvanic/voltaic- REDCAT cathode (+) cell electric potential is positive (spontaneous)

219
Q

At standard temperature and pressure (0°C, 1 atm), 1 mole of any gas will occupy _______ of volume.

A

22.4 L

220
Q

partial pressure=

A

mole fraction x total pressure

221
Q

The solubility is determined by Henry’s law

A

H = c/P The calculated solubility constants are (in units of μmol/L•atm)

222
Q

Ammeter

A

a device used to measure current

223
Q

Voltmeter

A

measures potential difference (voltage)

224
Q

total internal reflection can be calculated by putting one of the angles in snells law equal to 90 because sin(90)=1

A

This angle of incidence can be calculated via Snell’s Law: n1sinθcrit = n2sin90°

225
Q

Real images formed by just one lens will always be

A

inverted

226
Q

Virtual images formed by just one lens will always be

A

erect (aka right side up)

227
Q

n (index of refraction)=

A

c/v

228
Q

In humans, the clearest vision results when i

A

is equal to the distance from the lens to the fovea

229
Q

if an object is placed on the focal point (o = f) then

A

the image distance will be infinity, so no image will be seen 1/20 = 1/i + 1/20 1/i = 1/20 - 1/20 1/i = 0 i = ∞

230
Q

The lowest pitched sound will have the _______ frequency.

A

lowest

231
Q

Calculating Fundamental Frequency in a closed pipe (closed at one end open on the other)

A

(λ = 4L/n) With L=length of pipe and n = 1 because it is the fundamental frequency

An easier way to remember open and closed pipes is that yin a closed pipe you start with 1/4 wavelength as the fundamental frequency then keep adding 1/2 wavelength for following harmonics

For open pipes it is the same thing, but you start with 1\2 wavelength as the fundamental frequency then add 1/2 a wavelength for the following harmonics

232
Q

if a ray of light is entering and exiting glass where each side of the glass is the same substance (has the same n) then

A

angle entering is the same as the angle exiting on the other side

233
Q

bigger wavelength/ lower frequency means

A

the wave can travel through things and not bump, so speed is not as hindered by the molecules of the substance

234
Q

a wavelength entering a substance: more bumping molecules=

A

more refraction on the other side n=c/v v=velocity of light in a media (prism etc)

235
Q

n is not a property of the media, it is dependent on both

A

the wavelength of light entering and the media itself, so like blue light entering a prism bounces more than red light so it is slowed down more

236
Q

more refraction=

A

higher n

237
Q

f is positive when it is on the _____ side as the viewer

A

same the f (focal length) is nexative when on the opposite side of the viewer

238
Q

know if an image is virtual or real by looking at the sign of

A

i in the thin lens equation -=virtual +=real

239
Q

know if an image is inverted or upright based on sign of

A

m or magnification in m=-i/o formula

240
Q

fundamental frequency=

A

also known as first harmonic, it is the longest wavelength of a standing wave in a given tube aka the lowest frequency achievable in the given tube

241
Q

permittivity of water is ______ than that of free space

A

higher

242
Q

2 wires with currents are running parallel to eachother->

A

the magnetic fields don’t interact with eachother, rather the magnetic field of one interacts with the moving charge on the other wire if the force point from one to the other, then they attract, if the forces point away then they repel, you have to do both right hand rules to find where the force is pointing, first the curve hand rule then the flat hand rule

243
Q

in a parallel circuit the same ____ goes into each arm, but the ______ is variable based on the euqation V=IR

A

same=voltage dependent on resistance=current *important to note that the v going into each arm is the same, the I is varbale between arms, but within and arm the I is constant, even though different resistance resistors contribute different proportions of voltage drop

244
Q

For gases, higher temperatures result in behavior that is ________ ideal

A

more Generally, a gas behaves more like an ideal gas at higher temperature and lower pressure,[1] as the potential energy due to intermolecular forces becomes less significant compared with the particles’ kinetic energy, and the size of the molecules becomes less significant compared to the empty space between them.

245
Q

temperature is the approximation of….

A

average kinetic energy T ~ KEavg = ½mv2

246
Q

What is the relationship between wavelength and energy?

A

E = hf = hc/λ

247
Q

flow rate =

A

AV (cross-sectional area (velocity))

248
Q

Rydberg Equation

A

1/wavelength = R (1/n1^2 - 1/n2^2) used to calculate the emission wavelength of the emission when an electron goes from high to low energy levels

249
Q

log (x) = 6

A

x=10^6

250
Q

What does laminar flow look like?

A

Laminar flow is due to shear forces (friction) between the fluid and the solid surface of the tube. This results in layers having a gradient of velocities, in which the flow is the fastest in the middle of the tube (where friction is low) and slowest near the surface (where friction is high).

251
Q

what is the range of human hearing?

A

20 Hz to 20 kHz

252
Q

Henry’s Law

A

The solubility is determined by Henry’s law, H = c/P . The calculated solubility constants are (in units of μmol/L•atm) https://www.khanacademy.org/science/health-and-medicine/respiratory-system/gas-exchange-jv/v/henry-s-law

253
Q

apparent color of an object

A

is caused by the wavelengths of light that dont absorb, aka an absorbance peak for a wavelength means that the substance will NOT appear to be that color

254
Q

reflection and refraction

A

both occur when the wave encounters a different medium than the on it is travelling in, diffraction=changes path, reflection=bounces off the new medium

255
Q

Circumference of a circle

A

2πr

256
Q

Area of a circle

A

A=πr²

257
Q

SI base units

A

mass-kg, length-m, time-s, temp-K, amount of substance-mol, electrical current- A (ampere), luminous intensity - candela (cd)

258
Q

scalar quantity

A

A quantity in physics, such as mass, volume, distance, speed and time, that can be completely specified by its magnitude, and has no direction.

259
Q

when you take the square root of a decimal

A

it becomes a slightly larger decimal

260
Q

mechanical energy

A

KE + PE

261
Q

conservative force

A

A force, such as gravity, that performs work over a distance that is independent of the path taken.

262
Q

nonconservative forces

A

Forces that its work depends on the path. Eg: friction.

263
Q

One joule is equivalent to

A

one N∙m

264
Q

one newton is the same as one ____

A

(kg∙m)/s^2

265
Q

Watts are the unit for….. and are equivalent to…..

A

power

266
Q

efficiency

A

(useful work) / (energy in)

267
Q

laws of thermodynamics

A

The first law, also known as Law of Conservation of Energy, states that energy cannot be created or destroyed in an isolated system.

268
Q

work (dealing with pressure)=

A

PΔV

269
Q

A hoop and a sphere, each of mass M, are rolled down a frictionless ramp. At the bottom of the ramp, which object will have the greater translational velocity, and why?

A

An object’s moment of inertia contributes to its rotational kinetic energy. Since a higher moment of inertia correlates to a higher rotational KE, it also means that translational KE must be lower, as the sum of these two values must equal the potential energy at the top of the incline. For the sphere, more of its mass is concentrated towards the center than for the hoop. As a result, the sphere’s moment of inertia will be lower.

270
Q

If a gas is expanding in a container, then ____________.

A

it is performing work on a container

271
Q

work-energy theorem

A

whenever work is done, energy changes

272
Q

adabiatic

A

no heat or matter is added to the system/transferred

273
Q

Isobaric

A

constant pressure

274
Q

isothermic

A

constant temperature

275
Q

isochoric

A

constant volume

276
Q

Zeroth Law of Thermodynamics

A

If two thermodynamic systems are each in thermal equilibrium with a third, then they are in thermal equilibrium with each other.

277
Q

First law of thermodynamics

A

Energy can neither be created not destroyed but it may be converted from one form to another

278
Q

second law of thermodynamics

A

Every energy transfer or transformation increases the entropy of the universe.

279
Q

Third Law of Thermodynamics

A

No system can reach absolute zero, so can never have anything below 0 degrees kelvin

280
Q

Newton’s First Law

A

An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

281
Q

Newton’s Second Law

A

F=ma

282
Q

Newton’s Third Law

A

For every action there is an equal and opposite reaction

283
Q

Watts (units of power)

A

Joules/second

284
Q

frequency of oscillation

A

f = 1/2π [√(k/m)]

285
Q

Period of oscillation

A

inverse of frequency of oscillation

286
Q

Convex v Concave meniscus

A

concave-when interacts with the walls of the container more strongly than it does with itself

287
Q

scalar quantity

A

a quantity that can be described by magnitude only and has no direction

288
Q

units for electric potential

A

Volts or J/C (joules/coulomb)

289
Q

units for electric field

A

N/C or V/m

290
Q

charge has units of

A

coulombs

291
Q

electrostatic force has units of

A

newtons (like all forces)

292
Q

Period of a pendulum

A

T=2π√l/g

293
Q

elastic potential energy of a spring

A

U = ½ kx^2

294
Q

1 atm is equal to

A

101,500 Pa

295
Q

how do voltage and current go through parallel resistors

A

Voltage drops across parallel branches of a circuit are always identical; this idea forms the basis for Kirchoff’s second law. However, if the resistance values of the resistors are not equal, different amounts of current will pass through them. Specifically, more current will travel through the branch of lower resistance.

296
Q

of molecules in a mol

A

6 × 10^23 molecules

297
Q

charge of an ion

A

1.6 × 10-19 C/ion

298
Q

Capacitance

A

the ability of a conductor to store energy in the form of electrically separated charges

299
Q

a particle must have what to experience the effect of a magnetic field

A

it is evident that a particle must possess both velocity and a charge (whether positive or negative) to be affected by a magnetic field

300
Q

Lentz’s Law

A

Direction of the induced current is such that the induced magnetic field always opposes the change

301
Q

right hand rule for magnetic force

A

this is for positive charge, so if negative then flip

302
Q

what does not change when a wave goes from one media to another (and the two media have different densities)

A

frequency

303
Q

the decible scale is a logarithmic scale in which each 10 decibel interval, or a factor of 10, thus a 40 dB difference represents a _______ difference in intensity

A

10^4 or 10000

304
Q

total internal reflection occurs only when traveling from a material with a _______ refractive index to a material with a ________ refractive index

A

higher, lower

305
Q

convex mirrors have _____ focal lengths

A

negative

306
Q

convex mirrors always form ______ images

A

virtual

307
Q

Magnification equation

A

m = -i/o (negative because the image is inverted)

308
Q

radius of curvature is equal to

A

twice the focal length

309
Q

photoelectric effect

A

The emission of electrons from a metal when light shines on the metal

310
Q

when a uniform magnetic field is used to accelerate particles (this is used in mass spec) then what can be assumed…

A

-the particles are charged

311
Q

strong nuclear force

A

the attractive force that binds protons and neutrons together in the nucleus

312
Q

bulk modulus

A

numerical constant that describes the elastic properties of a solid or fluid

313
Q

velocity of a sound wave through a medium

A

v = √B/ρ

314
Q

relationship between intensity and decibels of sound

A

dB = 10 log (I/Iinitial)

315
Q

doppler equation

A

f’ = f (vsound ∓ vreceiver / vsound ∓ vsource). If the objects are moving closer together overall, the perceived frequency of sound should increase

316
Q

transverse v oscillating wave

A

longitudinal wave-This wave’s oscillation is forward-and-backwards in amplitude, while its overall direction of propagation is forward. Because the amplitude of oscillation is parallel to the direction of the wave’s motion, it is a longitudinal wave. ex slinky wave moving left to right if held straight perpendicularly

317
Q

c=

A

lamda(f)

318
Q

Energy of a wave

A

hf

319
Q

in a double slit when looking at the light bands of constructive interference, the bands must be

A

bright region on the optical screen must result from constructive interference. This tells you that the two waves involved must be completely in phase, or differ by exact multiples of a wavelength

320
Q

Which changes are experienced by visible light as it moves from Medium 1 (n = 1.16) to Medium 2 (n = 1.68)?

A

Wavelength decreases while frequency remains constant.

321
Q

When adding chemical reactions, the associated equilibrium constants can be

A

multiplied together to give the equilibrium constant for the overall reaction.

322
Q

SDS-PAGE-acts like a _____ cell, and negatively charged proteins move towards the ___________

A

electrolytic, positive anode

323
Q

electrolytic cell v galvanic/voltaic cell

A

https://www.khanacademy.org/science/chemistry/oxidation-reduction/electrolytic-cell/v/introduction-to-electrolysis

324
Q

At standard temperature and pressure (0°C, 1 atm), 1 mole of any gas will occupy _______ of volume.

A

22.4 L

325
Q

partial pressure=

A

mole fraction x total pressure

326
Q

The solubility is determined by Henry’s law

A

H = c/P

327
Q

Ammeter

A

a device used to measure current

328
Q

Voltmeter

A

measures potential difference (voltage)

329
Q

total internal reflection can be calculated by putting one of the angles in snells law equal to 90 because sin(90)=1

A

This angle of incidence can be calculated via Snell’s Law: n1sinθcrit = n2sin90°

330
Q

Real images formed by just one lens will always be

A

inverted

331
Q

Virtual images formed by just one lens will always be

A

erect (aka right side up)

332
Q

n (index of refraction)=

A

c/v

333
Q

In humans, the clearest vision results when i

A

is equal to the distance from the lens to the fovea

334
Q

if an object is placed on the focal point (o = f) then

A

the image distance will be infinity, so no image will be seen

335
Q

The lowest pitched sound will have the _______ frequency.

A

lowest

336
Q

Calculating Fundamental Frequency in a closed pipe

A

(λ = 4L/n)

337
Q

if a ray of light is entering and exiting glass where each side of the glass is the same substance (has the same n) then

A

angle entering is the same as the angle exiting on the other side

338
Q

bigger wavelength/ lower frequency means

A

the wave can travel through things and not bump, so speed is not as hindered by the molecules of the substance

339
Q

more bumping molecules=

A

more refraction on the other side

340
Q

n is not a property of the media, it is dependent on both

A

the wavelength of light entering and the media itself, so like blue light entering a prism bounces more than red light so it is slowed down more

341
Q

more refraction=

A

higher n

342
Q

f is positive when it is on the _____ side as the viewer

A

same

343
Q

know if an image is virtual or real by looking at the sign of

A

i in the thin lens equation

344
Q

know if an image is inverted or upright based on sign of

A

m or magnification in

345
Q

fundamental frequency=

A

also known as first harmonic, it is the longest wavelength of a standing wave in a given tube aka the lowest frequency achievable in the given tube

346
Q

permittivity of water is ______ than that of free space

A

higher

347
Q

2 wires with currents are running parallel to eachother->

A

the magnetic fields don’t interact with eachother, rather the magnetic field of one interacts with the moving charge on the other wire

348
Q

in a parallel circuit the same ____ goes into each arm, but the ______ is variable based on the euqation V=IR

A

same=voltage

349
Q

For gases, higher temperatures result in behavior that is ________ ideal

A

more

350
Q

temperature is the approximation of….

A

average kinetic energy

351
Q

What is the relationship between wavelength and energy?

A

E = hf = hc/λ

352
Q

flow rate =

A

AV

353
Q

Rydberg Equation

A

1/wavelength = R (1/n1^2 - 1/n2^2)

354
Q

log (x) = 6

A

x=10^6

355
Q

What does laminar flow look like?

A

Laminar flow is due to shear forces (friction) between the fluid and the solid surface of the tube. This results in layers having a gradient of velocities, in which the flow is the fastest in the middle of the tube (where friction is low) and slowest near the surface (where friction is high).

356
Q

what is the range of human hearing?

A

20 Hz to 20 kHz

357
Q

Henry’s Law

A

The solubility is determined by Henry’s law, H = c/P . The calculated solubility constants are (in units of μmol/L•atm)

358
Q

suffixes -ite and -ate

A

-ite (fewer O atoms NO2-) -ate (greater number of O atoms NO3-)

359
Q

Bohr Model

A

model of an atom that shows electrons in circular orbits around the nucleus

360
Q

Bohr/Rutherford experiment

A

also showed that energy is emitted and absorbed in discrete amounts called quanta which can be seen on an atomic absorption/emission spectrum

361
Q

when an electron jumps valence shells, the energy released can be modeled as:

A

E=(plank’s constant)(frequency of the light) E=hf or bc we know the frequency of a wave is equal to the speed of light in a vacuum (c) divided by its wavelength, we can say E=hc/wavelength

362
Q

frequency of light in a vacuum (c)

A

3.00x10^8 m/s

363
Q

energy (E) of an election at a certain energy level (n)

A

E=-Rydberg constant/ n^2

364
Q

energy emitted or absorbed as an electron moves between two energy levels

A

change in E= hc/wavelength=R(1/(nf)^2-1/(ni)^2)

365
Q

going from a low to high energy level is energy _______, while going from high to low is energy ______

A

absorption, emission

366
Q

Orbital shapes

A

s (spherical); p (dumbbell); d (double dumbbell plus donut); f (too complicated)

367
Q

principal quantum number

A

symbolized by n, indicates the main energy level occupied by the electron (row that element is on)

368
Q

azimuthal quantum number (angular momentum)

A

Second quantum number, designated l. Tells us the shapes of the electron orbitals, describes the subshell of the principle quantum number, ranges from 0 to n-1 l=0 (s) l=1 (p) l=2 (d) l=3 (f)

369
Q

magnetic quantum number

A

symbolized by m, indicates the orientation of an orbital around the nucleus (ranges from -l to +l)

370
Q

Spin number (m)

A

Spin of electron. Can be -1/2 or 1/2

371
Q

Saponification

A

usually use triacylglycerols: breaking down the esters formed between the -COOH groups of fatty acids and the -OH groups of glycerol under basic conditions

372
Q

Sphingolipids

A

Fatty acid residue bonded to a sphingosine, found on the outer side of the plasma membrane and play a crucial role in signaling systems

373
Q

Prostaglandins

A

(subcategory of eicosanoids) Modified fatty acids that are produced by a wide range of cells, synthesized from arachidonic acid, have 20 carbons and a 5 carbon ring, help regulate inflammation

374
Q

Terpenes and terpenoids

A

these are the precursors to steroids and other lipid signaling molecules and have varied independent functions Know: 1. Vitamin A is a terpene derivative 2. Squaline, a 30 carbon terpene, is a precursor for the synthesis of cholesterol, steroid hormones, and Vitamin D

375
Q

in eukaryotes, carbohydrates occur in their ____ isomers

A

D (D/L is based on the orientation of the glyceraldehyde and is not equivalent to either R/S or dextrorotary/levorotary

376
Q

sucrose

A

glucose + fructose

377
Q

Lactose

A

glucose + galactose

378
Q

Maltose

A

glucose + glucose

379
Q

mRNA

A

messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome

380
Q

tRNA

A

transfer RNA; type of RNA that carries amino acids to the ribosome

381
Q

rRNA

A

ribosomal RNA; type of RNA that makes up part of the ribosome

382
Q

hnRNA

A

Heterogeneous nuclear RNA; the primary transcript made in eukaryotes before splicing.

383
Q

siRNA

A

small interfering RNA, prevent the production of specific proteins based on the nucleotide sequences of their corresponding mRNA

384
Q

miRNA

A

A microRNA is a small non-coding RNA molecule found in plants, animals and some viruses, that functions in RNA silencing and post-transcriptional regulation of gene expression

385
Q

Epimers

A

A subtype of diastereomers that differ in absolute configuration at exactly one chiral carbon, so everything is the same except for one chiral center

386
Q

Diastereomers

A

stereoisomers that are not mirror images (not enantiomers)

387
Q

enantiomers

A

isomers that are mirror images of each other, so each chiral center has the oppostite configuration

388
Q

constitutional isomers (structural isomers)

A

compounds with the same molecular formula but different connections among their atoms

389
Q

rotamers

A

two or more different conformations of the same molecule that can be interconverted into one another by rotation around a single bond Rotamers are conformational isomers that differ by rotation about a single σ bond. (trans and cis)

390
Q

micelle

A

A small particle formed by aggregates of molecules with both polar and nonpolar segments (e.g., soap); the polar ends of these molecules point outward toward a polar solvent (e.g., water) while the non-polar ends will point inward toward a nonpolar solute (dirt/oil/grease). This allows the nonpolar substance to be washed away by the polar substance. fatty acids make these, but phospholipids and glycolipds are too bulky to form these

391
Q

energy denisities of macronutrients

A

fats (lipids)-9 kcal/g carbohydrates (sugars)-4 kcal/g proteins-4 kcal/g

392
Q

Aufbau Principle

A

the rule that electrons occupy the orbitals of lowest energy first

393
Q

nuclear shielding

A

concept of filled orbitals of e- between nucleus and valence e- reduce pull on valence e- by protons

394
Q

Avogadro’s number

A

6.02 x 10^23

395
Q

bond angles to know: bent (water)

A

104.5 degrees

396
Q

bond angles to know: trigonal pyramidal

A

107 degrees

397
Q

bond angles to know: tetrahedral

A

109.5 degrees

398
Q

bond angles to know: trigonal planar

A

120 degrees

399
Q

bond angles to know: linear

A

180 degrees

400
Q

VSEPR theory

A

Valence-shell electron-pair repulsion theory; because electron pairs repel, molecules adjust their shapes so that valence electron pairs are as far apart as possible

401
Q

trigonal planar

A

has 3 binding regions (no electron pairs)

402
Q

aluminum

A

is an exception to the quartet rule, makes 3 bonds

403
Q

bond length is determined by

A

the sizes (radii) of the two bonding atoms and how many electron pairs they share

404
Q

SN1 stereochemistry

A

In an SN1 reaction, the original stereochemistry of the molecule is lost when the carbocation intermediate (a planar structure) is formed. Thus, the product is present as a racemic mixture. Such a mixture includes each enantiomer in a 1:1 ratio, meaning that it promotes no net rotation of polarized light.

405
Q

epimer

A

These molecules differ at a single stereogenic center, classifying them as epimers.

406
Q

anomeric carbon

A

anomeric carbon (the carbon atom bound to two separate oxygen groups)

407
Q

E1 reaction-DONT NEED TO KNOW

A

E1 reactions are unimolecular eliminations. These reactions are analogous to SN1 mechanisms, as both are first-order and involve the formation of a carbocation. As such, both are heavily favored by tertiary reagents. Additionally, use of a mild or weak base tends to push a reaction toward E1, as E2 reactions (which are bimolecular) require moderately strong basic species. Finally, like SN1 processes, E1 reactions prefer protic solvents for carbocation stabilization.

408
Q

UV-visible spectroscopy

A

-An analytical technique involving measurement of the UV-visible light absorbed by a substance. -mainly used to analyze conjugated systems

409
Q

What would PCC oxide an alcohol to?

A

As a weak oxidizing agent, PCC will oxidize a primary alcohol to an aldehyde. According to IUPAC naming convention, this aldehyde group will be given the highest priority, so our numbering should begin at that end of the chain. The parent alkane is five carbons long, and our high-priority aldehyde is given the suffix “-al,” yielding “pentanal.” From there, the methyl substituents are numbered based on the carbons to which they are attached.

410
Q

What would CrO3 and K2Cr2O7 turn a primary alcohol into?

A

strong oxidants and will thus oxidize a primary alcohol directly to a carboxylic acid

411
Q

addition of pyridine (ring with an N in it)

A

(a weak base) will decrease the chance of this protonation, inhibiting carbocation formation

412
Q

which is a better acid ethanol, or ethanthiol

A

Since sulfur is much larger than oxygen, the conjugate base of ethanethiol is better able to delocalize negative charge, increasing its stability. Remember, the more stable the conjugate base, the stronger the acid.

413
Q

SN2

A

These processes, formally known as bimolecular nucleophilic substitution reactions, happen in one step and involve a “backside attack” by a strong nucleophile. Since the attacking atom must bind at the same time as the leaving group is removed, these reactions require an unhindered substrate.

414
Q

good leaving groups are

A

weak bases

415
Q

Can acetals form under basic conditions?

A

No, acetals cannot form under basic conditions. Under basic conditions, only hemiacetals can be formed. Acetals, which result from the reaction of a hemiacetal with an alcohol, require acidic conditions.

416
Q

Hemiacetals and hemiketals exist in equilibrium with

A

aldehydes and ketones.

417
Q

alpha hydrogen

A

An alpha hydrogen is one that is bound to the carbon immediately adjacent to a carbonyl carbon

418
Q

chromic acid

A

Chromic acid (H2CrO4), like many chromium-containing reagents, is a strong oxidizing agent. Reaction of a primary alcohol with such a compound will oxidize it as thoroughly as possible. Since a primary alcohol has only one bond to carbon, it possesses the ability to form three bonds to oxygen, creating a carboxylic acid.

419
Q

reducing agent NaBH4 turns an aldehyde into?

A

could turn an aldehyde into an alcohol

420
Q

kinetic v thermal product

A

The kinetic product is the one that is less thermodynamically stable, but is easier to synthesize due to a lower activation energy. In general, kinetic enolates are less substituted than their thermodynamic counterparts. Here, the double bond has formed in the position that is less sterically hindered (between carbons 1 and 6).If this were the thermodynamic enolate, it would have the double bond between carbons 1 and 2 (the more substituted position adjacent to what formerly was the carbonyl carbon).

421
Q

reducing agents

A

-Chemically, deuterium and hydrogen behave identically. Thus, lithium aluminum deuteride may be considered to be equivalent to lithium aluminum hydride (LAH). LAH is a strong reducing agent and is certainly capable of reducing both carboxylic acids and aldehydes. It would therefore be the most appropriate choice. -Sodium borohydride would be perfectly adequate for selective reduction of the aldehyde, but it lacks the reducing power necessary to reduce the carboxylic acid. -Sodium hydride is a strong base, but is not a hydride source and thus is not a reducing agent. -Potassium cyanide is a nucleophile and a weak base. It is not an appropriate choice for any reduction reactions.

422
Q

Thionyl chloride (SOCl2) is a

A

reagent commonly used to convert carboxylic acids into acyl halides

423
Q

Reaction of a carboxylic acid with an alcohol forms an

A

ester. Esters are nearly identical to carboxylic acids in terms of reactivity.

424
Q

halide leaving group stability

A

iodine serves as the best leaving group. To understand this concept, consider the periodic table. As a member of a much lower period than (for example) fluorine, iodine is a very large atom. As such, it can easily delocalize the negative charge gained when it exits as a leaving group. The better the leaving group, the more reactive the compound, and a more reactive molecule is by definition less stable.

425
Q

Reactivity of carboxylic acid derivatives

A

acid anhydride, one of the more reactive of the carboxylic acid derivatives. Esters, in contrast, are moderately unreactive, since their leaving groups are extremely unstable in solution

426
Q

When cyanide reacts with propanal (an aldehyde), it forms a

A

cyanohydrin. Interestingly, it is the carbon - not the nitrogen - atom that acts as a nucleophile to attack the carbonyl carbon. The final cyanohydrin product consists of the former carbonyl carbon bound to -OH, -H, the original -R group from the aldehyde, and -C≡N.

427
Q

Charles’ law states

A

that the volume of a gas is directly proportional to its temperature

428
Q

Dalton’s law

A

Dalton’s law states that the total pressure in a vessel is the sum of the partial pressures of the components. Moreover, the partial pressure of a gas is proportional to its mole fraction in the container.

429
Q

As increasing amounts of NaCl are added to water

A

boiling point will increase, melting point will decrease, and vapor pressure will decrease.

430
Q

metathesis reaction is synonymous with

A

a double displacement reaction in which two reactants exchange cations (also could think of it as two reactants switching anions)

431
Q

how to calculate oxidation state

A

https://www.khanacademy.org/science/chemistry/oxidation-reduction/redox-oxidation-reduction/v/practice-determining-oxidation-states (a hint that oxdation is occurring is if large amounts of oxygen are present)

432
Q

Avogadro’s number

A

6.02 x 10^23

433
Q

What is Keq?

A

[products]/[reactants] at equilibrium so if greater than 1 favors products

434
Q

Keq for reverse reaction

A

1/Keq

435
Q

Q is the reaction quotient

A

-it is the same formula as Keq, but the concentrations come from any point in time, not just during equilibrium -so if Q

436
Q

Le Chatelier’s Principle

A

States that if a stress is applied to a system at equilibrium, the system shifts in the direction that relieves the stress. stress= change in reactant or product concentrations, temperature, pressure, or volume

437
Q

if change in H is negative

A

the reaction is exothermic

438
Q

if a reaction is exothermic, then heat is a ___

A

product

439
Q

specific heat capacity

A

q=mcdeltaT

440
Q

change in H reaction

A

ERROR!

441
Q

Gibbs free energy

A

ERROR!

442
Q

exergonic reaction

A

Reaction that proceeds with a net release of free energy, so gibbs free energy is negative and reaction is spontaneous *to clarify beign spontaneous does not mean anything about the kinetics, or rate of reaction

443
Q

rate is a kinetic parameter and is largely determined by

A

activation energy (affected by enzyme catalysists)

444
Q

delta G of rxn =

A

-RTlnK R=8 T=kelvin ln(1)=0

445
Q

thermodynamic product

A

-is more stable -forms more slowly (favored when temp is high bc has enough energy to overcome the high activation energy barrier)

446
Q

kinetic product

A

-forms more quickly -less thermodynamically stable -lower activation energy -favored at low temperatures

447
Q

heat equation for for temperature change (not phase change)

A

q=mcdeltaT q=heat m=mass c=specific heat capacity of a substance (varies depending on the phase) delta T= temperature

448
Q

volume and temperature of a gas are directly proportional under constant pressure

A

V1/T1=V2/T2

449
Q

Ideal Gas Law

A

PV=nRT n=number of mols R=.08206L(atm)/(k)mol

450
Q

molality

A

mols of solute/kilograms of solvent

451
Q

Normality

A

molarity x # of H’s in the acid

452
Q

assumptions about ideal gasses:

A

-average KE is proportional to T -particles have no volume -particles exert no forces on each other

453
Q

nucleoside

A

nucleotides that lack attached phosphate groups

454
Q

substitution solvents

A

polar-facilitates polysubstitution nonpolar-facilitates monosubstitution

455
Q

acetal v hemiacetal

A

Hydrolysis of the acetal will yield a free aldehyde and two alcohols

456
Q

Tollen’s reagent

A

-detects presence of reducing sugar (if reducing silver is present then a silver coating forms) -uses Ag(NH3)2+ as oxidizing agent *in a + test, aldehydes reduce Ag+ to metallic silver

457
Q

cholesterol in physiological conditions

A

In eukaryotic cells in vivo, the role of cholesterol in the membrane is to provide fluidity within the otherwise rigid phospholipid structure.

458
Q

UV-Vis

A

typically used to assess the presence of highly conjugated systems

459
Q

Mass spectrometry peaks represent

A

mass-to-charge ratios. More specifically, mass spec involves the fragmentation and ionization of the molecule in question. Typically, this ionization simply entails the removal of one electron, leaving the mass of the fragment virtually unchanged.

460
Q

During a phase change, the temperature of a substance

A

stays the same

461
Q

the rate constant can be affected by:

A

activation energy and temp

462
Q

catalysis act by

A

reducing the activation energy (only affect kinetics not thermodynamics)

463
Q

Rate laws are determined by

A

experiment

464
Q

for a radical to form…

A

there usually needs to be an odd number of valence electrons in the molecule

465
Q

heterogenous catalyst

A

a catalyst whose phase is different from the reactants’, ex. a gas catalyst for a liquid reaction

466
Q

can reason out rate law constant (k) units, rate itself is M/s (which is on left side of equal sign)

A

then you just plug in molarity on the right side where there are concentrations

467
Q

Arrhenius acids

A

produce H+ ions in water

468
Q

Arrhenius base

A

Produces OH- ions when dissolved in water

469
Q

Bronsted-Lowry acid

A

proton donor

470
Q

Bronsted-Lowry base

A

proton acceptor

471
Q

Lewis acid

A

electron pair acceptor (electrophiles - Bf3, BCl3, AlCl3, and AIF3)

472
Q

Lewis base

A

electron pair donor

473
Q

Amphiprotic

A

A species that can either accept or donate a proton, so can act as either and acid or a base, ex. H2O which can become OH- or H3O+ also amino acids are an example

474
Q

amphipathic

A

having both a hydrophilic region (polar) and a hydrophobic region (non polar)

475
Q

Ka and Kb constants, (dissociation constants of acids and bases)

A

ratio of concentration of products to reactants, so the higher it is the stronger it is bc it has more dissociation

476
Q

strong acids

A

HCl, HBr, HI, HClO3, HClO4, HNO3, H2SO4 (not strong acids: HF, H2CO3, H3PO4)

477
Q

Strong bases include

A

LiOH, NaOH, KOH, RbOH, CsOH, Ca(OH)2, Sr(OH)2, Ba(OH)2

478
Q

pOH

A

-log[OH-]

479
Q

pH

A

-log[H+]

480
Q

when using pH scale, a shortcut to calculating pH is that if the concentration of [H+] is written in scientific notation, then the pH is the negative of the exponent

A

1 x 10^-4 pH would be 4

481
Q

pKa vs Ka

A

higher ka is a stronger acid but smaller pKa is a stronger acid, same relationship is true for bases, because K always refers to the disassociation (ratio of products to reactant concentration)

482
Q

(Ka)(KB)=

A

Kw=10•-14

483
Q

pKa+pKb=

A

pKw=14

484
Q

ICE table

A

Initial, Change, Equilibrium

485
Q

ICE tables what to add/subtract

A

https://www.youtube.com/watch?v=54n1XppP-lA

486
Q

For elementary reactions (or single-step), stoichiometric coefficients can be used to write the

A

rate law These coefficients become exponents according to the following theoretical example: for the reaction aA + bB → cC, rate = k[A]a[B]b.

487
Q

Keq can be found by

A

placing products over reactants, with each species raised to an exponent corresponding to its coefficient in the chemical reaction. (Note that all concentrations must be at equilibrium.) Solids and pure liquids are not included in this expression.

488
Q

Ksp

A

read this: https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Equilibria/Solubilty/Solubility_Product_Constant%2C_Ksp

489
Q

As an equilibrium constant, Ksp only responds to changes in

A

temperature

490
Q

The lower the value of the pOH of a solution, the more _____ the solution is.

A

basic (akaline)

491
Q

what forms a good buffer?

A

Equimolar amounts of a weak acid and its conjugate will form an ideal buffer. -not strong acids/bases

492
Q

relationship between pKa and Ka

A

pKa = -log(Ka)

493
Q

pH=

A

-log[H+]

494
Q

Henderson-Hasselbalch equation can be written as either

A

pH = pKa + log([A-]/[HA]) or pOH = pKb + log([HA]/[A-])

495
Q

less positive oxidation potential= less likely to oxidize

A

less positive oxidation potential; in other words, it is less likely to oxidize and the oxidation potential and reduction potential are inverses of each other

496
Q

electrolytic cell has to do with the reduction potential and you need to know wthat reduction occurs at the___

A

cathode reduction potential higher=more likely to be reduced and thus act as an oxidizer In electrolytic cells, the nonspontaneous redox half-reaction will take place thanks to the external current being applied. Since Al3+ has a more negative reduction potential than Cd2+, it is Al3+ that will reduce and Cd (s) that will oxidize. In contrast, in a galvanic cell, the reverse (spontaneous) redox half-reaction would take place. Oxidation and reduction always occur according to the mnemonic “REDCAT”: reduction happens at the cathode and oxidation takes place at the anode.

497
Q

IR O-H stretching region

A

3000 to 3700 cm-1,

498
Q

IR C-H stretching region

A

2800 to 3000 cm-1

499
Q

IR C=O stretching region

A

1700 to 1800 cm-1

500
Q

IR C-O stretching region

A

1200 to 1400 cm-1

501
Q

Where is the isoelectric point on a titration curve?

A

at the flat part (if there are many isoelectric points then it is the avergae of the two that are the closest together-the two closest should be either both acidic or both basic, of not then choose the ones that are both either acid/base)

502
Q

Although SPLET and SET-PT have similar total ΔH values, the first step in SET-PT has an especially high ΔH, meaning that it is particularly

A

unfavored

takeaway: even if total delta H is the same, if the first step of one reaction has a particularly high deltaH, it is more unfavorable than the other reaction with the similar deltaH

503
Q

velocity

A

displacement/time

504
Q

speed

A

distance traveled/time

505
Q

Vitamin B1 is best known as a ____

A

oenzyme in metabolic processes involving amino acids and carbohydrates.

506
Q

Vitamin E is an ______

A

antioxidant

507
Q

coenzyme A

A

transfers acyl groups from one place to another