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Science

Ionic bonding

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Ionic bonding occurs between positive and negative ions, which attract each other and bind together to form ionic compounds. For example, sodium chloride consists of Na+ ions and Cl- ions bound together.

Each ion is surrounded by oppositely charged ions held in place by electrostatic attraction and forming an ionic crystal lattice. The ions in a crystal lattice are very strongly bonded - a high temperature is required to melt the crystal.

Ionic bonding

There are several ways in which atoms chemically combine together to make compounds. One of these ways is called ionic bonding. Atoms turn into ions when they lose or gain electrons.

Metal ions

In some circumstances metal atoms may lose electrons. The atom then has more protons than electrons and so it will be positively charged, a positive ion.

Example: A magnesium atom may lose two electrons and become a Mg2+ ion.

Non-metal ions

Non-metal atoms may gain electrons and become negatively charged.

Example: An oxygen atom may gain two electrons and become an O2- ion.

Ionic bonding

Positive and negative ions attract one another and bind together forming a new substance. This is called ionic bonding.

For example:

Sodium chloride consists of Na+ ions and Cl- ions bound together.

Magnesium oxide consists of Mg2+ ions and O2- ions bound together.

Ionic compounds like magnesium oxide and sodium chloride have high melting points and do not conduct electricity when solid. They do conduct electricity when molten. Sodium chloride is soluble in water and the solution conducts electricity.

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