In order to get a reaction started the reactants of this type of reaction require the greatest amount of energy:
a. fusion
b. fission
c. physical
d. chemical

The answer is A. Fusion is a reaction type that in order to initiate the reaction a greatest amount of energy should be inputted. This reaction involves two or more atomic nuclei coming very close to each other then colliding and eventually joining to form a new nucleus. The energy needed to do this is very large.

The answer is !

Ithink this is what you meant. the temperature at which a liquid begins to boil is called the boiling point. the boiling point of water is 212°f or 100°c.  and at that point will start to turn into steam (gas)