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Forming ionic bonds

Positive and negative ions form when a reacts with a , by transferring . The oppositely charged ions are strongly attracted to each other, forming .

An explanation of ionic bonding

Dot and cross diagrams

A dot and cross diagram shows the transfer of electrons from metal 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 outer electron from a sodium atom transfers to the outer shell of a chlorine atom
Figure caption,
The outer electron from a sodium atom transfers to the outer shell of a chlorine atom
The electron transfer in sodium chlorine
Figure caption,
The electron from a sodium atom transfers to a chlorine atom

Modelling ionic bonding

The slideshow shows dot and cross diagrams for the ions in sodium chloride, magnesium oxide and calcium chloride.

Image gallerySkip image gallerySlide 1 of 6, Structures of a sodium atom and a chlorine atom., 1. Ionic bonding in sodium chloride

Question

Draw a diagram, with outer electrons only, to show how the electrons are transferred when magnesium chloride is formed from its elements.