Answer:
hydrate
Explanation:
when a hydrate is heated,it changes color due to the exothermic reaction taking place.the structure of the complex changes but not entirely.this result in the sample to to not dissolve completely and we can observe the small traces of the sample.
Basically all it is a nucleus splitting into smaller fragments and these fragments are almost equal to half of the original mass
Liquid :) it goes directly from a solid to a gas. Have a nice day!