Understanding Thermal Energy

What does each circle in the Thermal Energy Simulation represent?

• Atoms

• Molecules

• Drops of water

• Air particles

Why does food coloring spread faster in hot water than in cold water?

• Hot water is lighter.

• Molecules in hot water move faster.

• Food coloring dissolves better in hot water.

• There are more molecules in hot water.

What happens to the molecules of a substance when its temperature increases?

• They slow down.

• They stop moving.

• They move faster.

• They break apart.

Which of the following best explains why temperature affects molecular motion?

• Temperature changes the size of molecules.

• Higher temperatures give molecules more energy.

• Cold temperatures make molecules heavier.

• Molecules at higher temperatures attract each other.

What is a molecule?

• A single atom

• A group of atoms joined together

• A tiny particle of light

• A group of water drops

In the Simulation, what is one difference you notice between hot and cold samples of water?

• The cold sample has fewer molecules.

• Molecules in the hot sample move faster.

• Molecules in the cold sample are larger.

• The hot sample has more molecules.

Which of the following is true when a substance reaches absolute zero?

• The molecules stop moving entirely.

• The molecules move very fast.

• The molecules break apart.

• The molecules change shape.

When the molecules in a sample speed up, what happens to its temperature?

• The temperature increases.

• The temperature decreases.

• The temperature stays the same.

• The sample cools down.

What evidence from the Simulation helps explain the faster spreading of food coloring in hot water?

• Molecules in hot water are farther apart.

• Molecules in hot water are moving faster.

• Molecules in cold water are smaller.

• Molecules in cold water are slower to form.

Why do scientists use simulations like the Thermal Energy Simulation?

• To replace experiments completely

• To observe molecular motion more clearly

• To avoid working with dangerous chemicals

• To measure water temperature