Asap lot of

1.is a state of matter a physical change or an chemical change ?
2.why does heat go to coldest to hottest substance
3.what type of phase change occur when a substance change solid to gas?
4.what an ex of sublimation

1. physical change

2. Heat flows from the warmer to the cooler object until they are both at the same temperature. The slower molecules gain more thermal energy and collide with other molecules in the cooler object. This process continues until heat energy from the warmer object spreads throughout the cooler object.

3. Sublimation: the substance changes directly from a solid to a gas without going through the liquid phase.

4. "Dry ice" or solid carbon dioxide sublimes

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.