Atom is a neutral particle having one nucleus, an unimaginably small particle that could not be made any smaller and still behaves as a chemical system.
Atomic energy is a term used to describe the constitutive internal power of the atom, which was absorbed when formed.
The atomic number is a term used to describe the number of protons in the nucleus of an atom of a particular element.
Neutron is an electrically neutral subatomic particle with a mass approximately equal to one atomic mass unit; generally found within an atomic nucleus.
Nuclear fusion reactors is a term used to describe a future source of energy. Most stars including our own Sun released energy by nuclear reactions between light atoms at temperatures of millions of degrees.
Proton is a term used to describe a subatomic particle with a charge of +1 and a mass of approximately one atomic mass unit; generally found within an atomic nucleus.