14. several days after a snowfall, the roofs of some homes on your street have almost no snow on them, while the roofs on other homes are still snow covered. assuming they have all received the same amount of sunlight, give one reason for this observation related to thermal energy and insulation.

Different houses have different coverings on their roofs. Shingles absorb the heat into the tar which heats up melting the snow. Houses with metal covering may still have snow on the roof. Another possible reason may be the angle of the roof. A roof with a less angle allow the snow to slide off the roof easier, as a roof with a larger angle would not allow the snow to slide off and hence snow remains on the roof

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.