The compact, positively-charged nucleus of an atom contains two main types of subatomic particles: protons and neutrons. Orbiting the atom's nucleus are negatively-charged subatomic particles called electrons. The mass o... More »

Nuclear energy is stored in the nucleus of an atom and holds the nucleus together. Substantial amounts of nuclear energy are released when splitting or fusing nuclei. More »

The net electric charge of the nucleus of an atom is positive due to the presence of charge-carrying particles known as protons. The outer shell of the atom is negatively charged as a result of carrying electrons in a di... More »

The number next to isotopes signifies the sum of the number of protons plus the number of neutrons in the nucleus of an atom. For a particular element, the number of protons never changes, but the number of neutrons can ... More »

Both protons and neutrons are found in the nucleus of an atom. The third type of particle that an atom has, electrons, are found in orbitals outside of the nucleus. More »

Atoms become radioactive when they have an excess of protons or neutrons in the nucleus, leading to unbalanced internal forces, which the atom balances by emitting radiation. Atoms with a different amount of neutrons or ... More »

The subatomic particles of protons and neutrons are found in the nucleus of an atom. Protons are particles with a positive charge, while neutrons have no charge. Electrons, which have a negative charge, are particles tha... More »