(1.40-1.41) Ionic bonding + dot/cross diagrams

Describe how to draw dot and cross diagrams to show the formation of ionic compounds by electron transfer.

Draw circles with electrons on the outer shell to represent the atoms.

Look at the atomic number/valence number to find out the electron number.

Draw an arrow towards two circles- one with a full outer shell, the other without.

These circles should have brackets around them and have their charges written on the top right side.

What do dot and cross diagrams show?

The electrical configurations of the atoms before electron transfer has occurred and the electric configurations of the ions (and their charges) after electron transfer.

Describe ionic bonding in terms of electrostatic attractions.

The electrostatic attraction between positive ions and negative ions.

What happens during the reaction that forms an ionic compound?

The metallic bonds are overcome, leaving metal atoms. The covalent bonds between the molecules are overcome, leaving the non-metal as atoms.

Electrons are transferred to create full outer shells and are arranged into an ionic lattice, held together by ionic bonding.