When energy is needed in order for the reaction to happen, then that reaction is known as endotermic. When the reaction has as a result energy then it is exotermic. An example of an endotermic reaction would be photosynthesis, for an exotermic: combustion.
Answer:
It's the third option.
Explanation:
In order for the chemical equation to be correctly it needs the same number of atoms of each element on both sides of the equal sign
Majority can such as hydrogen H and oxygen O forming water H2O but uranium having extra neutrons to form plutonium and beyond simply can't because it will not last for a fraction of a second or spiral out of control and violently react like the little boy and the fat man (a uranium and plutonium nuclear weapon) so yes and no