Download Matter and Energy unit review answer key

Name
Date
Hr.
Matter and Energy Unit Review
1.
Describe the molecules for each of the following states of matter. Include the arrangement of the
molecules, their movement, and their shape, and volume.
Solid: Tightly
packed/ vibrate/ has a definite shape and definite volume
Liquid: Space
between particles/ slip past each other, moving over and under/ no
definite shape but does have a definite volume
Gas: random
arrangement/ particles bounce, collide, and move very freely/ has no
definite shape or volume
2.
What is needed to change from one state to another?
Add heat energy or take away heat energy
3.
Describe the three types of heat transfer. Include an example from class demonstrations for each.
Conduction:
Particles of matter are touching and transfer heat/ metal ball in fire expands so it
will no longer fit in the ring
Convection:
Transfer of heat in a liquid or gas – hot rises and cool falls/ beaker of hot water with
food coloring is placed in a beaker of cool water so we see the hot water rise
Radiation:
Transfer of heat by electromagnetic waves/ radiometer turns around when a light
shines on it
4.
Match the way heat energy transfers to the methods of popping corn.
a. Radiation
b. Conduction
c. Convection
5.
popping corn in a pan on the stove
popping corn in a hot air popper
popping corn in a microwave oven
What did we see happen in a closed system when we found the mass of a jar/ice and then the jar/water
after the ice melted?
Mass was not gained or lost as the water changed states. This is because nothing
was added nor taken from the jar.
6.
Explain the difference between potential energy and kinetic energy.
Potential energy is stored energy due to position and Kinetic energy is energy of
motion.
7.
Explain the relationship between potential energy and kinetic energy.
When you add potential and kinetic energy you get mechanical energy. If you
increase or decrease PE, KE will also increase or decrease
8.
Give five examples of potential energy and five examples of kinetic energy.
Potential
-fireworks with an unlit fuse
-stretched rubber band
-roller coaster at the top of a hill
-a cookie on a plate
-an archers bow when it is pulled back
9.
Kinetic
-football flying through the air
-rolling skate board
- a moving bike
- a hamburger after it has been eaten
- an arrow flying through the air
What is the formula for kinetic energy?
KE = ½ mv2 or KE = ½ mass x velocity2
Velocity is the same as speed in this formula
10. If a car and a semi-truck are traveling at the same speed, which one has more kinetic energy? Why?
The semi-truck because it has more mass.
11. What is the formula for mechanical energy? Give an example of a problem from your book or
worksheet.
ME = KE + PE
A basketball that has the KE of 6 J and the PE of 12 J
ME = KE + PE
ME = 6 J + 12 J
ME = 18 J
12. The Law of Conservation of Energy states that energy can be neither created nor destroyed by ordinary
means. What happens to the potential and kinetic energy of a bouncy ball if you drop it from a height of
10 meters and do not touch it until it stops? Think about the Law of Conservation of energy.
As the potential and kinetic energy change they are always equal to the same
total amount of energy. See the basketball example on page 95.