A dot and cross diagram models the transfer of electrons from metal atoms to non-metal atoms. The electrons from one atom are shown as dots, and the electrons from the other atom are shown as crosses. For example, when sodium reacts with chlorine, electrons transfer from sodium atoms to chlorine atoms. The diagrams show two ways of representing this electron transfer.
The slideshow shows dot and cross diagrams for the ions in sodium chloride, magnesium oxide and calcium chloride.
Draw a diagram, with outer electrons only, to show how the electrons are transferred when magnesium chloride is formed from its elements.