What type of ion is created when an atom gains electrons?

When an atom gains electrons, it becomes negatively charged. This negatively charged ion is known as an anion. The addition of electrons increases the number of negatively charged particles in the atom, which means there are now more electrons than protons. As a result, the overall charge of the atom shifts from neutral (where the number of protons equals the number of electrons) to negative.

In contrast, a cation is formed when an atom loses electrons, resulting in a positive charge due to having more protons than electrons. A neutral atom maintains an equal number of protons and electrons, maintaining a balanced charge. A radical, on the other hand, refers to an atom or molecule that has unpaired electrons and is typically very reactive, which does not directly relate to the simple gain of electrons to form an ion.