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```					                                        7th Grade
Physical Science Benchmark Test

1- The theory that explains the movement of molecules suggests that:
a) molecules do not move                       b) only gas molecules move
c) only liquid molecules move                  d) gas, liquid, and solid molecules move

2- The definition of matter is:
a) anything that has mass and volume            b) anything that can be felt
c) anything that is a solid                     d) none of the above

3- If significant energy is removed from a liquid, which drawing below shows what the molecules would
look like after the energy was removed?
Error! Reference source not
found.

A                                       B                                      C

4- An atom is:
a) the smallest unit of matter                          b) mostly empty space
c) too small to be seen                                 d) all of these

5- The reason we have had so many models of atoms throughout history is:
a) scientists can make 3-D models now               b) scientists use better methods now
b) scientists have better technology now            d) previous scientists were misinformed

6- If the drawing below represents a model of an atom, which part would represent the electron?

A

B

C

7- What happens to the density of a balloon (tied at the bottom) when heat energy is added:
a. The density increases because the volume of the balloon increases

b.   The density decreases because the volume of the balloon increases

c.   The density decreases because the mass decreases
d.   There is no change in density, only in volume

8- Which of these is evidence that particles of matter are in constant motion:

a.   Tiny dust specks move around in a beam of light from a flashlight

b.   Food coloring spreads evenly throughout a beaker of water

c.   Both a and b are evidence of particle motion

d.   Neither a nor b are evidence of particle motion

9- Ryan is given the following items: a rock, sand, water, and metal bar. Ryan calculates the density
of each object . The results are as follows: Rock = 3.2 g/mL, Sand = 1.9 g/mL, Water = 1.0g/mL,
Piece of metal = 6.5 g/mL . Ryan then puts all of the items into a jar and shakes it up. He lets the jar
settle for 5 minutes. What would be the expected order of the items going from the top of the
container to the bottom?
a. rock, sand, water, metal                                b. metal, rock, sand, water
c. water, sand, rock, metal                                d. sand, metal, water, rock

You are given an unknown object. You find its mass to be 28g. You find its volume to be 10 mL. Using
the chart below, answer questions 10 and 11.

Layer                      Approximate Density
Water                         0.9 - 1.3 g/mL
Crust                         2.7 – 3.0 g/mL
Mantle                        3.3 – 5.7 g/mL
Outer Core                    9.0-12.0 g/mL
Inner Core                    12.7 – 13.0 g/mL

10- What is the density of the unknown object?

a.    28 g                b. 10 ml            c. 2.8 g/ml           d. cannot be determined

11- Where would this object belong if it were compared to the earth densities above?

a.   Water               b. crust         c. mantle                d. atmosphere

12- Why are iron and nickel found in Earth’s core?
a. They have a higher density than most of Earth’s substances.
b. They have a lower density than most of Earth’s substances.
c. The core is hotter than the other layers of the earth.
d. The core is colder than the other layers of the earth.

13- A beach is composed of particles of sand of the same size. Why doesn’t the beach have materials of
all sizes? The particles have
a. come from the same place.                          b. come to the beach at the same time.
c. been found in underwater canyons.                  d. been sorted by size and density.
14- Sand with particles of the same size was gently shaken in a jar to see if layers would form. What
variable was being tested?
a. particle size        b. particle density    c. particle color           d. particle type

You are given the following materials and their densities and then asked to construct a model of the earth
consisting of a core, mantle, crust, water, and air. Use this chart to answer the next two questions:

Cotton                  0.2 g/mL
Glue                   1.0 g/mL
clay                   1.8 g/mL
Aluminum foil               2.4 g/mL
A Quarter                 4.6 g/mL

15- Based on density, which material would be the best choice to represent the core of the Earth?
a. cotton        b. clay          c. aluminum foil         d. quarter

16- Based on density, which material would be the best choice to represent the crust of the Earth?
a. cotton        b. clay          c. aluminum foil         d. quarter

17- Water is added to a jar with soil in it and the jar is shaken. Which drawing shows what will happen
after it sits for several minutes?
a.                        b.                      c.                    d.

18- A streambed contains round rocks, all about the same size. Why are there no smaller particles of
sand and clay? Sand and clay
a. are denser.                                b. have washed away.
c. were never there.                          d. are too small to see.

19- An egg sinks in water but floats in salt water. What do you know about the density of the egg?
a. It is more dense than water but less dense than salt water.
b. It is less dense than water and less dense than salt water
c. It is denser than water and denser than salt water.
d. It is less dense than water but more dense than salt water.

20- A metal lid was very tightly screwed onto a glass jar. To get the jar open, Kelly held the lid under hot
water. Why was Kelly able to remove the lid?
a. Metal particles move more rapidly when heated so the particles moved farther
apart, and the lid increased in size slightly.
b. Metal particles move less rapidly when heated so the particles moved closer
together, and the lid decreased in size slightly.
c. The metal particles did not move. The water loosened the lid.
d. The metal particles melted because the water was so hot.

21-What happens to liquid water as it sits in an ice cube tray in the freezer?
(Careful, water is not like most substances.)
a. The liquid water loses energy and the particles move closer together

b.   The liquid water loses energy and the particles move farther apart as they turn

c.   The liquid water gains energy and the particles move closer together

d.   The liquid water loses energy and the particles move farther apart as they turn

22- If a used cat litter box is placed in a closed bathroom over the weekend, then the door to the
bathroom is opened which direction will the net movement of “stink” particles go?
a. Stink particles will not move, but clean-air particles will come in to make it smell better

b.   Stink particles will spread out and move out of the bathroom to make it smell better

c.   Stink particles will stay in the bathroom and it will always stink

d.   Stink particles will die to make it smell better

23- Why do railroad tracks have a gap between the metal rails?
a. Because the summer heat makes the rails expand

b.   Because the summer sun makes the rails contract

c.   Because the winter cold makes the rails expand

d.   Because the winter cold makes the rails contract

24- Why does diffusion happen faster in hot water than in the same amount of cold water?
a. Because the molecules of a gas are moving faster than the molecules of a liquid

b.   Because the molecules of a liquid are in constant motion

c.   Because the molecules of a liquid move faster when they are heated

d.   Diffusion doesn’t happen faster in hot water.

Use the following scenario to answer the next three questions:

At the District Science Fair, you notice a display board with a project on skateboards. You are interested
because you think skateboarding is cool. The student doing the project listed this as his procedure:

Step 1- gather a skateboard, a 5 kg bag of flour, a 25 kg bag of flour, a bungee cord, & stopwatch
Step 2- time the skateboard as it rolls down from the garage door to the gutter on my driveway
Step 3- strap the 5 kg bag of flour to the skateboard with the bungee cord
Step 4- repeat the timing procedure down the same driveway
Step 5- remove the 5 kg bag and strap the 25 kg bag of flour to the skateboard with the bungee
Step 6- repeat the timing procedure down the same driveway
Step 7- repeat steps 2 through 6 three times

25- What variable was this student trying to test? (The independent variable)
a. the length of the driveway                            b. the shape of the skateboard

a.   the speed of the skateboard                             d. the weight of the skateboard
a. the length of the driveway                         b. the shape of the skateboard

c.   the speed of the skateboard                            d. the weight of the skateboard

27- Is this a good experiment set-up?
a. Yes, because the student controlled all of the variables except one

b.   Yes, because the student tested something with a skateboard

c.   No, because the student didn’t do the test in a lab.

d.   No. because the student didn’t conduct background research first.

28- Your teacher gives you a small, jagged stone and asks you to calculate its mass and volume. Which
instruments would you use in order to make the measurements?
a. microscope and graduated cylinder           b. graduated cylinder and triple beam balance
c. triple beam balance and ruler               d. ruler and microscope

29- Which line on the graph shows what happens to molten lava as it cools. Assume that the numbers
represent temperature in degrees Celsius.

30- How has technology influenced our discoveries of the structure of the earth?
a. Satellite technology has allowed us to see what is inside the earth

b.   Infrared (heat sensing) technology has allowed us to measure the temperature of the earth

c.   X-Ray technology has allowed us to see the rock layers within the earth

d.   Seismograph (earthquake sensing) technology has allowed us to calculate the thickness and
density of the layers within the earth.

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