Ionic bonding

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.

Reactions between metals and non-metals include:

  • sodium + chlorine → sodium chloride
  • magnesium + oxygen → magnesium oxide
  • calcium + chlorine → calcium chloride
  • lithium + oxygen → lithium oxide

In all 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 – this is called an ionic bond.

The slideshow shows ionic bonds being formed in sodium chloride, magnesium oxide, calcium chloride and lithium chloride.

Sodium atom with 11 dot electrons and chlorine atom with 17 cross electrons.