Fades into outer space
no clear upper boundary
not all scientists agree that it is part of atmosphere
The phrases above are describing what layer of our atmosphere?

since electrons are negative the answer is neagtaive

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.