chem test 4 Flashcards
1
Q
nuclear reactions
A
reaction that affects the nucleus of an atom
2
Q
nuclear fission
A
heavy nucleus splits into more stable nuclei, occurs in bombs/reactors, low mass combines to form more stable and heavier atom, happens in stars
3
Q
chain reactions
A
starting material is made as product so reaction continues to happen
4
Q
alpha
A
particle w/ 2 protons and 2 neutrons bound together and had positive charge. similar to helium. lowest penetrating abilities. 4/2He and 4/2a.
5
Q
beta
A
an electron. more power than alpha. has negative charge. 0/-1B or 0/-1e.
6
Q
positron (beta positive)
A
positivity charged beta particle. 0/+1e
7
Q
neutron
A
has symbol 1/0n
8
Q
gamma y
A
no mass and no charge. js energy. highest penetrating power. 0/0y
9
Q
balancing nuclear reactions
A
mass number and atomic numbers on each side must be equal.
10
Q
what radiation has the greatest penetrating power?
A
gamma
11
Q
least penetrating power to the greatest penetrating power
A
alpha particle, gamma ray, beta particle
12
Q
in order of increasing mass
A
electron → proton → alpha particle
13
Q
What is the mass number of an alpha particle?
A
4
14
Q
Which of the following particles has the least mass
A
beta
15
Q
Which nuclear emission has no charge and no mass
A
gamma
16
Q
Which nuclear emission has the greatest mass
A
alpha
17
Q
Which type of radiation is identical in mass and charge to a helium nucleus
A
alpha
18
Q
Which particle has the greatest mass?
A
alpha
19
Q
Which nuclear decay emission consists of energy, only?
A
gamma
20
Q
Artificial transmutation is brought about by using accelerated particles to bombard an atom’s
A
nucleus
21
Q
A beta particle may be spontaneously emitted from
A
an unstable nucleus
21
Q
A change in the nucleus of an atom that converts the atom from one element to another element is called
A
transmutation
21
Q
Alpha particles and beta particles differ in
A
D) both mass and charge
22
Q
What is the name of the process in which the
nucleus of an atom of one element is changed into
the nucleus of an atom of a different element?
A
transmutation
23
Which of these types of nuclear radiation has the
greatest penetrating power?
gamma
24
radioactive
nucleus will spontaneously decompose
25
alpha decay
alpha particle is created
26
beta decay/beta negative/electron emission
beta particle is created
27
positron decay/beta positive emission
positron is created
28
nuclear decay occurs bc the nucleus of the atom is
unstable in current form/radioactive
29
the nucleus will proceed to transmutate until it is
nonradioactive
30
decay can happen in _ steps. each step can be different type of decay, or take different amount of time bc each has its own half life
one or many
31
half life
time required for half of og sample of nuclei to decay
32
periodic
repeatable pattern
33
atomic radius
size of atom, or how far the electrons are from the nucleus
34
how does atomic radius change
down + left +
35
biggest atomic radius element
francium
36
smallest atomic radius element
fluorine
37
why does atomic radius size decrease as you move to the right and increase as u move down?
down = more electron shells and bigger radius
right = less protons so less electrons in nucleus
38
electronegativity
ability of the atom to attract electrons when in a bond with another atom
39
most electronegative element
fluorine
40
least electronegative element
francium
41
how does electronegativity change
up + right +
42
y is fluorine better at attracting the electrons than francium?
the smaller an atom, the closer its electrons are to the nucleus. they are more attracted the closer they are to the nucleus, and vis versa
43
ionization energy
energy needed to lose one electron (creating a cation)
44
how does ionizing energy increase
up + right +
45
highest ionizing energy element (hard to lose electron)
fluorine
46
lowest ionizing energy element (ez to lose electron)
francium
47
why is it so easy for Francium to lose an electron and so hard for Fluorine to lose an electron?
fluorine is the smallest, meaning the electrons are closer to the nucleus and harder to get away, and vis versa
48
VSEPR
valence shell electron pair repulsion
49
electron pairs around a central atom will...
get as far apart from each other as possible
50
tetrahedral
4 surrounding atoms. 0 lone pairs. bond angle 109.5*. AB4
51
linear
180* AB2. 2 atoms are bonded together, or 2 surrounding atoms and 0 lone pairs are bonded.
52
trigonal planar
3 surrounding atoms and 0 lone pairs. bond angle 120*. AB3
53
trigonal pyramidal
3 surrounding atoms and 1 lone pair. <109.5*. AB3E
54
bent or angular
2 surrounding atoms and 1 or 2 lone pairs. <120* if 1 lone pair or much less than 109.5* if 2 lone pairs. AB2E or AB2E2
55
polarity
2 poles
56
whats a pole
poles of a magnet or two sides of different charge
57
what does it mean if a molecule is polar
one region of the molecule has a positive charge, and another has a negative charge (separation of charge)
58
how do we create polartiy
when electrons are shared unequally in a covalent (2 non metals) bond. (electrons are attracted to one atom instead of another)
59
how do we know which atom the electrons are attracted to in polarity?
look at the electronegativity of the atoms
60
in order to find if a bond is polar, look at the difference between the _ of the two atoms
electronegativity
61
non-polar covalent
<0.3 and equal sharing
62
polar covalent
0.3
63
ionic
<1.7 en
64
how do u know if a molecule is polar?
draw lewis dot and look at the shape. draw arrows facing more electronegative atoms.
65
dipole movement
a measure of how unequal the distribution of electric charge is in a molecule
66
if arrows point in same direction in dipole movement...
they are additive and all electrons move to that side, and we create different charged areas (polar!)
67
if arrows point in opposite direction... (away or towards each other)
cancel each other out, the electrons are equally moved around and we have the same charge everywhere (nonpolar!)
68
state of matter: solid
molecules are close, locked in place, vibrate, and crystalized in place
69
types of crystalline structures
ionic solid, molecular solid, atomic solid
70
ionic solid
crystal is made of separate ions and is a repeating pattern of positive and negative ions
71
molecular soild
crystal is made of individual molecules that bond together
72
atomic solid
crystal is made of individual atoms that bond together
73
liquid
molecules are close but can move. they r not stuck together well, and can escape to gas phase (vapor pressure)
74
75
Solid
molecules are very close connected, and locked in place and can only vibrate to move. they usually form a very specific structure called crystalline solid. (crystalized in place)
76
crystalline structures types
ionic solid, molecular solid, atomic solid
77
ionic solid
the crystal is made of separate ions, and is a repeating pattern of positive and negative ions
78
molecular solid
the crystal is made of individual molecules that bond together
79
atomic solid
the crystal is made of individual atoms that bond together
80
liquids
molecules are still close to each other but now have more freedom to move. they are not as stuck as solids, and can escape to gas phase (vapor pressure)
81
gases
molecules are completely separate and have ultimate freedom to move around. they are independent of each other, and have many properties
82
intermolecular forces
the forces that connect and separate molecule of a substance together
83
the stronger intermolecular forces are, the harder it is to...
separate the molecules
84
ionic intermolecular force
opposite charges on magnets pull on each other
85
hydrogen bonding intermolecular force
hydrogen + F, N, or O
86
dipole dipole bonding intermolecular force
polar / non even
(one molecule is positive and one is negative)
87
london dispersion bonding intermolecular force
non polar / even
(not all molecules have dipole)
88
polarity
lewis dot. draw arrows toward more electronegative element, to represent the direction the electrons are moving
89
dipole
the arrangement of charges of a molecule. + -. the force between N and S
90
if dipole arrows point in the same direction...
they are additive. all electrons move the the same side and different charges are created (polar)
91
if dipole arrows point in different directions (towards or away from each other)...
they cancel each other out and the electrons are equally have the same charge everywhere (non polar)
92
polarity
the property when there are two poles
93
what is a pole
poles of a magnet or two sides of different charge
94
for a molecule to be polar...
one side has to have a positive charge and the other negative (separation of charges)
95
how do we create polarity?
when electrons are shared unequally in a covalent bond. the electrons are attracted to one atom more than the other
96
how do we know which atom the electrons are more attracted to?
the more electronegative one
97
non-polar covalent bond
equal sharing; en<0.3
98
polar covalent
unequal sharing; 0.3
99
ionic
1.7
100
VSEPR
valence shell electron pair repulsion
101
linear
- 2 atoms 180* AB2
- 2 surrounding atoms (3 total) 0 lone pairs 180*
102
trigonal planar
3 surrounding atoms, 120*, AB3, 0 lone pairs
103
tetrahedral
4 surrounding atoms, 0 lone pairs, 109.5*, AB4
104
trigonal pyramidal
3 surrounding atoms, 1 lone pair, <109.5*, AB3E
105
bent/angular
2 surrounding atoms, 1 or 2 lone pairs
- 1 LP = <120* and AB2E
- 2 LP = <109.5* and AB2E2
106
what does phase diagram show
how pressure and temperature affect the 3 phases of matter
107
triple point
a point where all 3 phases intersect, solid, liquid, and gas exist at same time
108
critical point
liquid and gas coexist in new type of fluid called supercritical fluid
109
melting
solid to liquid
110
freezing
liquid to solid
111
vaporizing
liquid to gas
112
condensation
gas to liquid
113
sublimation
solid to gas
114
deposition
gas to solid
115
joule
standard unit of measurement for energy
116
caloire
amount of energy required to raise temp of 1 gram of water by 1*C
117
how many cal is 1 J
1 cal = 4.184 J
118
potential/stored energy
the energy that is bonding atoms and molecules togeether
119
if energy is released...
there is less energy stored in the chemical bonds
120
if energy is absorbed...
more energy is stored in the bonds
121
evaporation
molecules at surface of liquid are able to break free of their forces and turn into gas molecules
122
boiling
molecules inside liquid stare can separate and turn into gas molecules
123
specific heat capacity
amount of energy required to change the temp of 1 gram of substance by 1*C, and is different for each substance and the state of matter
124
heat curve
shows us how a substance is changing phase over time compared to the temperature change, shows what temp a phase change occurs
125
temperature is related to kinetic energy... meaning
the faster a molecule moves, the higher the kinetic energy/temp
126
pressure
force exerted over an area
127
barometer
used to measure pressure from the atmosphere. its filled with mercury
128
how does a gas apply force?
the force is when a molecule collides with the side of a container
129
what are the gas laws
a way to relate pressure, volume, and temp of a gas. describes how if u change one variable, it will affect the other variables and allow u to see changes in them
130
temperature definition
how fast particles move
131
pressure definition
how often particles collide with container
132
volume definition
how much space particles take up
133
boyles law
there's a connection between pressure and volume. they are inversely related, so if u increase one the other will decrease
134
charles law
there is a connection btwn volume and temp. they are directly related, so if u increase one then the other will also increase
135
directly related meaning
if u increase one factor, the other will also increase
136
inversely related meaning
if u increase one part, the other will decrease
137
gay lussac's law
there is a connection btwn pressure and temp. pressure and temp are directly related. one increase the other increase
138
combined gas law
pressure(1) x volume(1) / temp(1) = pressure(1) x volume(2) / temp(2)
139
more pressure means ___ collisions
more collisions
140
less volume means __ pressure
more pressure
141
more temp means ___ particles
faster particles
142
faster particles means __ volume and _ collisions
more volume/less collisions
143
more movement means __ temp
higher temp
144
what is temperature?
how fast particles are moving
145
can temperature be negative?
no
146
absolute scale
a scale in which numbers can only be positive
147
what is the absolute scale for temperature?
kelvin scale
148
whats the lowest temperature possible?
zero kelvin
149
if temperature is zero, particles are...
no longer moving (hard to achieve, and no experiment has EVER done it)
150
avogadro's law:
there is a connection between volume and number of moles of a gas.
151
more moles = __ space
more space
152
if moles increase, volume _
increases
153
number of moles and volume are ___ related
directly related (one increase the other increase)
154
by looking at combined gas law and adding avogadro's law, we learn that any gas can be described by its_, _, _, and _
pressure, volume, temp, number of moles
155
P(pressure)V(volume) =
n(number of moles) R(0.08206) T(temp in K)
156
what is the volume of a 1.00 mole of a gas at STP?
22.4L
- if we are not at STP we have to use the ideal gas law equation
157
ideal gas law equation
PV = nRT
158
when at STP, 1atm=_K, and 1mol gas = _ L
273, 22.4L
159
when not at STP, use _ to find the number of moles
stoichemetry
160
dalton gave us _ theory and law of _ _
atomic theory
law of partial pressure
161
law of partial pressure
pressure a gas exerts is the same if it is in a mixture of gases or by itself
162
partial pressure
the pressure of an individual gas when its in a mixture
163
vapor pressure
pressure of a gas
164
ideal gas law for law of partial pressure
ntotal = n1 + n2 + n3
n = PV/RT
Ptotal = p1 + p2 + p3
PtVt/RTt = P1V1/RT1 + 2 + 3 . . .
165
mole fraction
mole of gas 1 / total moles of mixture
x1 = n1 / ntotal
166
partial pressure formula
mole fraction x Ptotal
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