Group 0 — The Noble GasesAQA GCSE Chemistry: Revision notes

The periodic table arranges elements in order of atomic (proton) number, so elements with similar properties fall into the same column, or group. Group 0, the noble gases, includes helium, neon, argon, krypton, xenon and radon.

All noble gases share one key feature of atomic structure that explains their shared behaviour.

Noble gas atoms have a stable electron arrangement — their outer shell is already full. Helium has 2 outer electrons (a full first shell); all the others have 8 outer electrons.

Because there is no tendency to gain, lose or share electrons, noble gases:

• Exist as single, separate atoms (monatomic)
• Do not readily form bonds or react with other substances
• Are used where an unreactive atmosphere is needed, e.g. filling light bulbs, providing an inert atmosphere for welding

Unlike Group 1 and Group 7, Group 0 elements do not show a reactivity trend, since they are all essentially unreactive. Instead, the key trend is physical:

Boiling point increases going down the group, as relative atomic mass increases and the weak intermolecular forces between atoms become slightly stronger.

This is why helium boils at a much lower temperature than xenon.

An element's position in the periodic table reflects the arrangement of electrons in its atoms. For Group 0, this means:

• All members have a full outer shell, so all are unreactive
• Physical properties like boiling point follow a predictable trend with increasing atomic mass

This allows chemists to predict the likely properties and behaviour of a noble gas from its position in the group, even without direct experimental data.