Susanna heats up a sample of red crystals while the sample is being heated and gas is released in a blue powder is left after the heating is a sample of red crystals and element or compound please explain the answer

Sample response: Susana's red crystal sample is a compound because it was broken down into a gas and blue powder. It is not an element because elements cannot be broken down into simpler substances by ordinary means, such as heating.

This is late but if anyone needs it here you go.

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.