May someone please help me! thank you

How could a student test the effect of removing heat from a gas that is stored in a sealed container? what must occur in order for matter to change states?

Which statement is true about a catalyst? a: a catalyst decreases the rate of the reaction. b. a catalyst is consumed during a chemical reaction. c. a catalyst lowers the activation energy of a reaction. d. a catalyst increases the reactant concentration during a reaction.

Rays from the sun are not considered matter true or false