Question

The atoms and molecules that make up substances are always in motion. What happens when heat or thermal energy is added to a substance?

the particles move faster


the particle movement doesn't change


the particles move slower


the particles stop moving

Answer 1

the particles move faster

Step-by-step explanation:

When a substance is heated, it gains thermal energy. Therefore, its particles move faster and its temperature rises.

Answer 2

the particles move faster

Step-by-step explanation:

When heat is added to a substance, the molecules and atoms vibrate faster. As atoms vibrate faster, the space between atoms increases. The motion and spacing of the particles determines the state of matter of the substance. The end result of increased molecular motion is that the object expands and takes up more space.