Answer: Atoms (ions) are held together in an ionic bond through Electrostatic attraction
Explanation: Ions are atoms that lose or gain one or more electrons to become either positively or negatively charged, which are called anions and cations respectively. The cations are usually metals while anions are usually non-metals.
The bond (ionic bond) is formed when there is a transfer of valence electron(s) between the anion and the cation in order to obtain a full valence shell for both atoms.
Example of an ionic compound is NaCl.
Where: Na is the cation that looses a valence electron to become stable to Chlorine which is the anion that gained an electron to become stable.