1. The ionic linkage between atoms in which each accepts or donates electrons so that every atom ends up with a completed electron shell.
2. The combining power of an element, measured by the number of electrons one atom of it acquires from or transfers to another atom during the formation of a chemical compound.
3. The number of electrons which an atom tends to lose or to accept by transfer in a chemical reaction.
4. The number of positive or negative charges that an atom acquires by transferring its electrons to another atom to form a compound.

This is the chemical bond that results from such a process; an ionic bond.