The unit for energy is the joule (J). If the energy content of an object is 1,000 J, but then later it is found to be 900 J, what happened to 100 J of its energy? A) Energy was destroyed.

B) The object transferred some of its energy to its surroundings.

C) Energy was created.

D) The object absorbed additional energy from its surroundings.

they both have a y in them

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.