Does decomposing water require high activation energy

The four giant gas points that are made primarily of lightweight elements are

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.

Determine the age of a fossil if it had only one eighth of its original carbon-14 content remaining?