8th Grade Science - Test 7




The following test has 10 questions.

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1.



Mary has two blocks. She wants to compare the mass and the volume of both, so she places them in identical buckets filled with the same volume of water. Each block sinks slowly, and the picture above shows them as they are about to sink. She measures the change in water level with rulers.

Refer to the text and picture above to answer questions 1 through 3.

Mary infers that block A has more mass. Why might she be mistaken?
  a. Block A might have less density than water.
  b. Mary must first determine the length of block B.
  c. An object`s mass can be determined only if its density is known.
  d. The difference in water levels may be the result of different volumes.




2. If block B sinks to the bottom of its bucket and block A does not, which of the following must be TRUE?
  a. Block B has greater density and block A has greater mass.
  b. Block B has greater volume and block A has greater mass.
  c. Block B has greater density and block A has greater volume.
  d. Block B has greater volume and block A has greater density.




3. Mary's friend observes the investigation and claims that block B has more mass. If there were no errors in the investigation, which of the following must be TRUE for this claim to be correct?
  a. Block B must be larger than block A.
  b. Block B must be longer than block A.
  c. Block B must have more volume than block A.
  d. Block B must have greater density than block A.




4. The diagram below shows a Bunsen burner heating a beaker of water on a beaker stand. The arrows represent the transfer of heat energy in the water.



Which process is primarily responsible for the transfer of heat indicated by the arrows in the beaker of water?
  a. conduction
  b. convection
  c. radiation
  d. condensation




5. The diagram below shows a metal spoon in a glass of water.



Which process causes the metal spoon to appear split or broken?
  a. absorption
  b. refraction
  c. convection
  d. reflection




6. Which object represents a simple machine?
  a.

  b.

  c.

  d.




7. The diagram below shows a model of a sample of gas particles at room temperature.



Which diagram best shows the results of removing heat from this sample until it freezes?
  a.

  b.

  c.

  d.




8. A drain cleaner consists of sodium hydroxide and aluminum. When the drain cleaner is added to water, bubbles of hydrogen are produced, and the solution becomes very hot. Which of these best describes what happens to form the bubbles when the cleaner is added to water?
  a. A chemical reaction
  b. Condensation
  c. A physical change
  d. Evaporation




9.

In the picture above, a boy is trying to pull a dog on a leash, but the dog and the boy are moving in the same direction. Which of the following best describes the forces in this situation?
  a. The forces are balanced, and the net force is zero.
  b. The forces are unbalanced, and the boy’s force is greater.
  c. The forces are unbalanced, and the dog’s force is greater.
  d. The forces are balanced, and the dog is stronger than the boy.




10. The diagram below shows a hammer being used by a person to remove a nail from a piece of wood.



The hammer is being used as which type of simple machine?
  a. wheel and axle
  b. inclined plane
  c. lever
  d. pulley





Good Luck!