# Explain why scientists classify helium, neon, and argon as noble gases and describe one use of a noble gas that depends on its unreactive nature.

> OCR A-Level Chemistry B: Salters (H433) — EL Elements of life · Explain · 5 marks

> The noble gases are found in Group 0 of the periodic table. They make up a small but important fraction of the Earth's atmosphere and have several practical applications in everyday life.

## Mark scheme (5 marks)

1. Noble gases have a full outer shell of electrons
2. Because their outer shell is full, they do not need to gain, lose, or share electrons
3. Therefore noble gases are (chemically) unreactive / inert
4. Correct named use of a noble gas, e.g. argon used in light bulbs / welding, helium used in balloons / airships, neon used in advertising signs
5. The use described depends on the noble gas being unreactive / inert, so it does not react with the material or surroundings, e.g. argon in a light bulb prevents the filament from burning/oxidising

## Key terms

- [noble gases](https://www.gradenine.co.uk/glossary/noble-gases)
- [unreactive](https://www.gradenine.co.uk/glossary/unreactive)

## Related

- [Revision notes for OCR A-Level Chemistry B: Salters (H433)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-scientists-classify-helium-neon-f4786fbd) · Published by Druglandscape Ltd.