Two adams of the same element with different mass numbers are called?

neutrons
electrons
isotopes
nuclei

Isotopes! (I think) because neutrons are a part of an adome nuclei is the middle of a atom and a electron is what make electricity posiple

catya that's not even a b or c

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.