Thermal energy transfers from colder materials to hotter materials.

• True

• False

Which of the following best describes the cause of thermal energy transfer when ice is put inside water?

• Molecules/Atoms colliding with each other

• Energy moving from one place to another.

_____________ easily and quickly transfer thermal energy.

• Insulators

• Conductors

___________ minimize the transfer of thermal energy.

• Conductors

• Insulators

Faster-moving nitrogen molecules have less thermal energy than slower-moving nitrogen molecules.

• True

• False

Which state of matter is the best insulator?

• Solids

• Liquids

• Gases

Slower-moving water molecules have more thermal energy than faster-moving water molecules.

• True

• False

A hot gas molecule collides with a cold water molecule. SELECT ALL THAT ARE TRUE:

• After the collision, the hot gas molecule will move slower, and the cold water molecule will move faster.

• After the collision, the hot gas molecule will move faster, and the cold water molecule will move slower.

• After the collision, the hot gas molecule will gain thermal energy, and the cold water molecule will lose thermal energy.

• After the collision, the hot gas molecule will lose thermal energy, and the cold water molecule will gain thermal energy.

Cold water is heated in a hot metal pan. Cold water molecules collide with hot solid molecules. SELECT ALL THAT ARE TRUE

• After they collide, the cold water molecules will move slower, and the hot solid molecules will move faster.

• After they collide, the cold water molecules will move faster, and the hot solid molecules will move slower.

• After they collide, the cold water molecules will gain thermal energy, and the hot solid molecules will lose thermal energy.

• After they collide, the cold water molecules will lose thermal energy, and the hot solid molecules will gain thermal energy.

Why are gases good insulators?

• They don't transfer thermal energy well because they are moving so quickly.

• They don't transfer thermal energy well because they are moving so slowly.

• They don't transfer thermal energy well because they have a low density which means fewer molecular collisions to transfer the thermal energy.

• They don't transfer thermal energy well because they have a high density which means more molecular collisions to transfer the thermal energy.