Explanation:
chemical changes
>produce new substances w/ different chemical structure/ properties
> thermal energy can be used to BREAK bonds (endothermic)
>thermal energy can be transferred to a chem rxn to help form new products (endothermic)
> heat can be released by an exothermic chemical reaction (excess energy- the total energy used to break bonds is less than energy released in forming new bonds)
physical changes
>does not result in new substances (typically changes in state- solid, liquid, gas)
> thermal energy can be transferred to EVAPORATE water (add thermal E... water (liquid) to steam (gas)) or FREEZE water (remove thermal E... water (liquid) to ice (solid))
