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Compared to other elements, the noble gases are inert - they are extremely unreactive and do not take part in chemical reactions.

Explaining the inertness of noble gases

The table shows the electronic structures of some noble gases. All the noble gases have complete outer shells:

• helium has only two electrons
• the other elements have eight electrons in the outer shell

When elements react, their atoms complete their outer shells by losing, gaining, or sharing electrons. Atoms of group 0 elements already have stable arrangements of electrons. This means that they have no tendency to lose, gain, or share electrons. This is why the noble gases are unreactive. It also explains why atoms of group 0 elements do not share electrons to form molecules.