The answer would be a. Energy stored in chemical bonds :)
Answer:
Answers, in order:
40, Temperature steeply decreases, 2, Effect decreases steeply, 5 and 9, 10
I'm assuming your test is done by now, but the answer is B. An ion forms when an atom has a positive or negative charge. In other words, an atom is an ion whenever the amount of protons and electrons are unequal.