When metals react with non-metals, electrons are transferred from the metal atoms to the non-metal atoms, forming ions. The resulting compound is called an ionic compound.
Consider reactions between metals and non-metals, for example:
- sodium + chlorine → sodium chloride
- magnesium + oxygen → magnesium oxide
- calcium + chlorine → calcium chloride
In each of these reactions, the metal atoms give electrons to the non-metal atoms. The metal atoms become positive ions and the non-metal atoms become negative ions.
There is a strong electrostatic force of attraction between these oppositely charged ions, called an ionic bond.