8th Grade Physical Science Final Review

In making a cake, which process involves a chemical change?

a. mixing ingredients for the batter

b. slicing strawberries for the topping

c. spreading frosting on the cake

d. baking the batter to form the cake

A baseball strikes the roof of a car and dents it. The paint on the roof begins to crack and chip, exposing the metal. The exposed metal on the roof rusts, eventually causing a small hole in the roof. Which event is NOT a physical change?

a. the paint cracks and chips
b. the exposed metal rusts
c. the rook of the car dents
d. the baseball strikes the roof

Heat will continue to transfer between two areas or objects until

a. both areas/objects are the same temperature
b. the melting point is reached
c. all heat energy is lost to the air
d. the colder object absorbs all of the heat energy

Which of the following is formed when two elements combine chemically?

a. an electron
b. a atom
c. a compound
d. a mixture

What is the smallest unit of a chemical compound that still has the properties of that compound?

a. a nucleus
b. a molecule
c. an element
d. an atom

A student is given a sample of an unknown liquid to test in the laboratory. The student thinks that the liquid is water. Which of the following physical properties of the sample is most helpful to determine if the liquid is water?

a. the color of the liquid
b. the mass of the liquid
c. the volume of the liquid
d. the boiling point of the liquid

In chemistry, the elements are

a. Pure chemical substances containing only one type of atom
b. Pure chemical substances containing two or more different types of atoms
c. Substances which can be burnt in the presence of air
d. Substances which do not react with other substances

Which of the following do water (H2O), rust (Fe2O3), and salt (NaCl) have in common?

a. Water, rust and salt are atoms.
b. Water, rust and salt are mixtures.
c. Water, rust and salt are elements.
d. Water, rust and salt are compounds.

Which statement best describes the energy changes that occur while a child is riding on a sled down a steep, snow-covered hill?

a. Kinetic energy decreases and potential energy increases.
b. Kinetic energy increases and potential energy decreases.
c. Both potential energy and kinetic energy decrease.
d. Both potential energy and kinetic energy increase.

At what point in its fall does the kinetic energy of a falling object equal its potential energy?

a. at the start of the fall
b. halfway between the start and the end
c. at the end of the fall
d. at all points during the fall

The liquid in a thermometer rises when the temperature increases. This is because the particles in the liquid

a. move faster and spread apart
b. lose heat energy and condense
c. move slower and spread apart
d. lose heat energy and evaporate

Which of the following sets of tools would be most useful in an experiment measuring the rate of transfer of thermal energy in four different liquids?

a. Triple-beam balance, beakers, metric ruler
b. Hot plate stove, beakers, thermometers
c. Microscope, funnel, metric ruler
d. pH meter, test tubes, forceps

Use Newton’s second Law of Motion to calculate how much force would be necessary to move a 100 kg object at a speed of 2 m/s2.

a. 50 N
b. 200 N
c. 102 N
d. not enough information

For an object to remain at rest, which of the following must be true?

a. The forces on it are balanced.
b. There is no friction.
c. Gravity does not act on it.
d. The object has no mass.

Read the following statements. Which one is NOT a great illustration of Newton’s 3rd Law of Motion?

a. Firefighters hold hoses firmly because as the water shoots out, the hose is pushed back.
b. A car speeding on the highway slows down when they see a police car.
c. A cannon jumps back as it is fired by a soldier.
d. When you sit in your chair, your body exerts a downward force on the chair and the chair exerts an upward force on your body