States of Matter and Temp scientific term

The state of matter which changes into liquid state by heating.(scientific term)

The state of matter which changes into liquid state by cooling.

What is the scientific term for the increase of the size of a substance due to increasing its temperature?

What is the scientific term for the decrease of the size of a substance due to decreasing its temperature?

What happens to the spaces between molecules when a liquid is frozen?

What happens to the spaces between molecules when a liquid is heated?