Help please, thank you.

Why is alchemy not considered to be a science ?

In the image, the arrow is pointing to a celestial object. which attribute disqualifies the object from being a planet?

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.