Final Exam Flashcards
If a scientist studies new ways to make batteries for electric cars, it is considered…
Technology
According to the textbook, what question is answered by science?
How?
For scientific study, which of these must occur?
a. testing and logic
b. philosophy and psychology
c. understanding and wisdom
d. observation and testing
d. observation and testing
In science, facts ______ _________.
can change
What can be used to explain many phenomena within a particular area of science?
Theories
If pulled rapidly, a tablecloth can be pulled out from under a table full of dishes without the dishes moving. This is because the dishes have…
inertia.
A car and a truck are speeding down I-24 at 75mph. The ______ has more inertia because it has more ______.
Truck; mass
If you go to the moon, your mass would…
be the same as on earth.
What is defined as a push or a pull?
Force
A book is sitting on a table without moving. What is true of the force on the book?
The net force on the book is zero.
the only difference between speed and velocity is…
velocity includes direction and speed does not.
If a car is driving towards the south and the net force on the car is toward the north, the car will…
Slow down
A rock is dropped from a tall cliff under free fall conditions. How far will the rock fall in 4 seconds?
80m
d=1/2gt^2 = 1/2 (10)(4)^2 = 80m
A rock is dropped from a tall cliff under free fall conditions. How fast will the rock be falling 3 seconds after it is dropped?
30m/s
v = gt = 10(3) = 30m/s
Which of these is not true about free fall (on earth)?
a. acceleration is 10m/s
b. an object will reach terminal velocity if it falls far enough.
c. the only force is gravity.
d. all objects fall at the same rate.
b. An object will reach terminal velocity if it falls far enough.
Newton’s Laws of Motion indicate that if an object is in motion and the net force is zero, the object will…
continue in a straight line at the same speed.
what is the weight of a box whose mass is 20kg?
200 N
w = 20(10) = 200N
If a feather and a rock are dropped under free fall conditions,
the rock and the feather will hit the ground at the same time.
If a feather and a rock are dropped and they fall through the air,
the rock will hit the ground first.
Which of these is not true about terminal velocity?
a. acceleration is zero.
b. all objects fall with the same velocity
c. velocity is constant
d. weight = air resistance
b. all objects fall with the same velocity
True or false, if a ball is rolling down a ramp, the support force will be straight up.
False, the support force will be perpendicular to the surface of the ramp - at an angle.
True or false, if a ball is rolling down a ramp, the gravitational force will be straight down.
True
If a ball is rolling down a ramp, the frictional force will be ____________________.
up the ramp.
A box is sitting on a table with a force of 25N to the left and 5 N to the right. What is the net force on the box?
20N to the left.
A box is sitting on a table with a force of 25N to the left and 5 N to the right. Assume the box is sliding to the left when these forces are applied. The box will….
Speed up.
A box is sitting on a table with a force of 25N to the left and 5 N to the right. If the box is being pushed to the left, the frictional force is…
25N
A man kicks a soccer ball. According to Newton’s 3rd law, what is the reaction force?
The ball hits the man’s foot.
If a circus performer falls into a net they are not hurt, but if they fall directly onto the floor they are hurt. This is because falling into a net…
causes their momentum to change over a longer period of time.
For an object to have momentum, it must have both mass and __________.
Velocity.
If momentum changes over a short period of time,
a large force is required to cause the change in momentum.
Energy due to height is…
Potential energy.
Power is measured in _________.
Watts.
Energy is measured in ________.
Joules.
A circus performer is high on a platform. He dives off the platform towards the floor. As he falls, his potential energy is converted to…
Kinetic energy
When we “use all of our energy resources”, what is happening?
we are converting useful forms of energy into non-useful forms of energy.
True or false: there is a gravitational attraction between you and the pencil you are holding.
True.
True or false: if I go into deep space beyond our solar system, there is still a gravitational attraction between me and the earth.
True
We know that there is less gravity on the moon than on earth. This means,
the moon has less mass than the earth.
In the space station, astronauts are weightless because…
they do not have a supporting force.
The horizontal motion of a projectile is controlled by…
inertia
A man shoots an arrow. Without gravity, the arrow would follow a straight-line path. With gravity, after two seconds it will be ______ below that straight-line path.
20m
d = 10(2) = 20m
A spaceship is in a circular orbit around the earth. What will happen if it decreases its speed?
It will fall to the earth
The speed of a satellite in a circular orbit ________________________________.
Is always the same
A satellite in an elliptical orbit is fastest when it is _______________________.
closest to the earth.
The earth is in ____________________.
An elliptical orbit
In a fluid, pressure is greater at the _______ of the fluid.
bottom
According to Archimedes’ Principle, the buoyant force is equal to….
the weight of the water displaced by the object.
An object with a density of 0.9g/mL will ________ when placed in water.
Float
A piece of metal shaped into a bowl is able to float on water because…
it displaces more water
The pressure of a gas in a container is caused by…
the gas molecules hitting the walls of the container.
A typical atmospheric pressure is…
760 mm Hg
(also 14.7 psi, 1 atm, or 30 in Hg)
a person is able to suck a drink into a straw because…
air pressure pushes the drink into the straw after the air is sucked out of the straw.
A helium balloon rises into the air when released because…
Helium has a lower density than air.
An airplane wing is designed to make the airflow slower _______ the wing.
under
Where is air pressure greatest during a severe storm?
inside a house
On which temperature scale is absolute zero actually equal to zero?
Kelvin
When the temperature of a substance is increased….
the molecules in the substance move faster
True or False: scientists have never reached absolute zero, but they are very close and could reach it in the near future.
False, scientists will never reach absolute zero.
Heat is measured in _________.
Joules
True or False: on a cold winter day, the cold moves through the window to the inside of the house.
False, heat flows outside through the glass in the windows.
By natural processes, entropy _________.
increases
Water has a heat capacity that is ________ _______.
unusually high
When the humidity is high and there is lots of water in the air…
there is a small difference between daytime and nighttime temperatures.
Some lakes never freeze in the winter even though they are in very cold areas. Why is that?
The lake is too deep, and all the water never cools to 4 degrees celcius.
Ice has a _______ density than liquid water.
lower
convection occurs __________________________________.
primarily in liquids and gases
A hot drink is placed in a cup. What causes the outside of the cup to gradually get hot?
conduction
In convection, a cool gas _______.
sinks
Areas with a desert climate generally exist where the air tends to _______.
sink
Because the sun is hot, it emits light with _______ wavelengths.
short
X-rays are able to penetrate into our body because they have _________ wavelengths.
short
What greenhouse gas is formed when we burn fossil fuels?
Carbon dioxide
When steam condenses to a liquid, it _________ energy.
releases
When a solid is converted directly to a gas, it is called _______________.
sublimation
When we sweat, the sweat cools our body primarily by the process of ___________.
evaporation
A proton has __________ charge
positive
two electrons are _________ _____ one another.
repelled by
Electric current is due to the flow of ___________ through a wire.
electrons
amperes are related to…
the number of charges that flow through a circuit in one second.
Silicon serves as a(n) ___________________.
semiconductor
If a substance has no resistance, it is called a(n) ____________________.
superconductor
The wires in a space heater need to have relatively ________ resistance.
high
True or False: All working electrical devices have a magnetic field around them.
True
An external source of energy is used to spin a turbine, which causes a coil of wire to spin between two magnets. This is the basis of ______________________.
a generator
Batteries provide ____ current.
DC
Light waves are ____________ waves.
transverse
A bright light has high ___________.
amplitude
Sometimes sound travels farther than at other times. What causes this?
refraction
the siren of a fire truck has a __________ frequency when the truck is coming toward you.
higher
a green leaf absorbs light that is _______.
red
when mixing paint, which colors work best?
the subtractive primary colors (maroon, yellow, and cyan)
What color is between orange and green in the visible spectrum?
yellow
the appearance of a pencil in water is distorted due to _________.
refraction
Which color of light is scattered most by nitrogen and oxygen molecules?
blue
an example of dispersion is ____________.
a rainbow
Which particle has a charge of -1?
Electrons
Which particle is found in the nucleus of an atom?
protons and neutrons
How many elements are found in nature?
90
Which particles have a mass of 1amu?
protons and neutrons
the mass of an atom is determined by the number of…
protons and neutrons
the identity of an element is determined by its number of …
protons
Which of these is a transition metal?
a) Mg
b) Si
c) Ti
d) U
c) Ti
Which of these is a metalloid?
a) Mg
b) Si
c) Ti
d) U
b) Si
What group is Sulfur (S) in?
16
Uranium-235 and Uranium-238 differ in the number of…
neutrons
Which of these elements would you expect to be a better conductor of electricity?
a) Zn
b) P
a) Zn
Which of these atoms is the largest?
a) Li
b) F
c) Cs
d) At
c) Cs
Which of these elements is most likely to be malleable?
a) Ni
b) N
c) Br
a) Ni
If an element is a gas at room temperature, it is a…
nonmetal
When electrons go into an atom, which shells are filled first?
Those closest to the nucleus
The line spectrum of an element is the result of _____________ moving to different energy levels.
Electrons
Which process can be used to treat cancer?
Radioactivity
Which process uses hydrogen as a fuel source?
Fusion
Which process is referred to as “splitting the atom”
Fission
Which process occurs in the sun?
Fusion
Which process is used in nuclear power plants?
Fission
Which type of radiation is represented by the symbol 0/-1B?
Beta
Which type of radiation is most able to penetrate into our bodies?
Gamma
Which type of radiation consists of two protons and two neutrons?
Alpha
An isotope has a half-life of two days. If you start with 1000g of this isotope, how much will be left after four days?
250g
Transmutation refers to…
converting one element to a different element
Ionizing radiation knocks __________ out of atoms.
electrons
A free radical…
has an unpaired electron in it
radiation is most likely to affect ___________-growing tissue.
fast
The age of a ___________ could be determined by carbon-14 dating.
bone
Where does energy come from in fission?
a small amount of mass is converted to energy
In fission, the chain reaction is caused by ___________.
neutrons
True or false: The most common type of nuclear reactor in the United States is a Breeder Reactor.
False
What is the purpose of a control rod in a nuclear reactor?
it absorbs excess neutrons
The fuel pellets used in a nuclear power plant must be…
below critical mass
which process requires a very high temperature?
fusion
True or false: Fusion reactors are common in the united states.
false
True or false: Fusion produces more pollution than fission
false
Cl2 is…
an element
CO2 is…
a compound
Density is an example of a ___________ property.
physical
Give the symbol for each of these elements:
a) The alkali metal in period 4
b) The element in group 4a and period 3
c) The noble gas in period 5
a) K (potassium)
b) Si (silicon)
c) Xe (xenon)
For each of the following substances, give its correct name using either guideline 1 or guideline 2.
a) K2O
b) SiCl4
c) BeF2
a) Potassium Oxide
b) Silicon Tetrachloride
c) Beryllium Flouride
An ionic compound is described as atoms ___________ electrons.
Donating
How many valence electrons does Si have?
4
When Mg forms an ion, it becomes a __________ with a charge of ___________.
cation; +2
An O-2 ion has ___________ ___ electrons when compared to an oxygen atom with no charge.
gained 2
What is the correct formula for an ionic compound formed between Ca and Br?
CaBr2
Which of the following is a covalent compound?
a. NaCl
b. SO2
c. AgCl
d. ZnHg
b. SO2
In a double bond, two atoms are sharing ________ electrons
4
How many bonds does an N atom typically form?
3
Polar covalent bonds are a result of…
two atoms sharing electrons unequally.
Water is considered a ________ compound.
Polar
Water dissolves…
polar and ionic compounds
When compared to other molecules of approximately the same size, water has an unusually ______ boiling point.
high
Pure copper wire is a(n) ____________.
element
When salt is dissolved in water, it forms a transparent, uniform mixture. This is an example of a…
solution
Milk is an example of…
suspension
Pure water is an example of a…
compound
when salt is dissolved in water, water is the __________.
solvent
a concentrated solution has a __________ solute.
a lot of solute
a mole is…
6.02 X 10^23
Molarity is…
a way to indicate the concentration of a solution
The molar mass of CH2O is…
30g/m
How many grams are in 0.75 moles of NO2?
34.5g
How many moles are in 500g of NO2?
10.9 mole
When the following equation is balanced, what is the number in front of the Ag?
_____ Ag + _____ Cl2 –> _____ AgCl
2
In the following reaction, what are the reactants?
CH4 + 2O2 –> CO2 + 2H2O
CH4 and O2
When two substances react, the reaction gets very hot. this is an example of an ______________ reaction.
exothermic
a catalyst speeds up a reaction by…
decreasing the activation energy of the reaction
increasing the concentration of the reactants…
makes the reaction occur faster.
a reaction occurs faster when the temperature is increased because…
there are more collisions of the reactant molecules.
a base is a proton ____________.
acceptor
when a substance is added to water, the amount of hydronium ion in the water increases. This substance is a(n) _______.
acid.
In the following reaction, H2O is the ________.
H2O + NH2- –> OH- + NH3
acid
according to chemistry, a salt is…
an ionic compound formed when an acid reacts with a base..
A neutral solution has a pH of?
7
A solution with more hydroxide ion than hydronium ion is…
basic
a solution with a pH of 6 is…
acidic
rainwater with a pH of 5.5 is…
not considered acid rain.
The most devastating effects of acid rain are typically found downwind from ___________________.
Powerplants
When an atom is reduced, it _________ electrons.
gains
true or false: in batteries, it is required that one substance is oxidized while another substance is reduced.
true
Nickel metal hydride batteries are…
rechargeable
Alkaline batteries are…
not rechargeable
an oxidation-reduction reaction involving oxygen and a non-metallic material is called _____________.
combustion
metals are often protected from oxidation by attaching __________ to the surface of the metal.
Zinc
