1. A bond between atoms or groups that carry opposite charges; or, in some cases, partial charges.
2. A chemical bond in which one atom loses an electron to form a positive ion and the other atom gains an electron to form a negative ion,
3. A valence bond in which two atoms are kept together by electrostatic forces caused by transferring one or more electrons from one atom to another atom.

A valence is the combining power of atoms or groups measured by the number of electrons the atom or group will receive, give up, or share in forming a compound.

1. A type of chemical bond in which atoms of different elements join by transferring one or more electrons from one to the other to form an ionizing or polar compound.BR> 2. A chemical bond characteristic of salts and formed by the complete transfer of one or more electrons from one kind of atom to another atom.
3. A type of chemical bonding in which one or more electrons are transferred completely from one atom to another, and so converting the neutral atoms into electrically charged ions.

These ions are approximately spherical and attract one another because of their opposite charge.