why do we need to study the different types of conditionals in stating hypothetical situation and their consequences

Is it possible to use the energy from two atoms colliding to create a clean burning lasting fuel source with a large amount of force? is it also possible to harness that energy from the two atoms colliding to create a clean energy source that will last for years from just two atoms colliding. is there a possibility to control and store that energy for years but slowly let the energy out enough to power cities cheaper and faster.

When a spring is compressed, the energy changes from kinetic to potential. which best describes what is causing this change? work power gravitational energy chemical energy

What is a neurotransmitter involved in mood reward, addiction, and motor behaviors?