Question

When a substance changes from one phase to another, which of the following occurs?

The substance loses or gains heat.

The average kinetic energy of the substance changes.

The temperature of the substance changes.

The molecular motion of the substance changes.

Answer 1

when you heat something up
what do you give to it?
meaning what do u give to the atoms of the substance u r heating up?

Answer 2

aren't the 1st and 3rd the same thing...?

Answer 3

The molecular motion of the substance changes.
Take the example of water. In ice (a solid) the H2O molecules are very rigid and vibrate slowly, but don't move much. In liquid water, the H2O molecules are more fluid, but still connected to each other, and move faster, which allows the H2O molecules to take the shape of the container (or lack thereof). In water vapor (gas), the H2O molecules are moving very quickly and zip around the container it is in or room and may run into each other, and these molecules aren't "connected" to each other anymore. (but still keep the H2O form).

Answer 4

yeah pretty much 1 and 3 are same so u can exclude them