# Methane (CH₄) is a hydrocarbon and the simplest member of the alkane homologous series. Explain what is meant by the term homologous series and describe two features that all alkanes share as members of the same homologous series.

> WJEC GCSE Chemistry (Wales) — 2.6 Carbon chemistry / organic chemistry · Explain · 4 marks

## Mark scheme (4 marks)

1. A homologous series is a family/group of compounds that share the same general formula (and differ by CH₂ each time).
2. All alkanes have the same general formula (CₙH₂ₙ₊₂).
3. All alkanes contain only single (C–C and C–H) bonds / are saturated.
4. All alkanes have similar chemical properties (and their physical properties show a gradual trend / boiling point increases with increasing chain length).

## Key terms

- [homologous series](https://www.gradenine.co.uk/glossary/homologous-series)
- [alkane](https://www.gradenine.co.uk/glossary/alkane)

## Related

- [Revision notes for WJEC GCSE Chemistry (Wales)](https://www.gradenine.co.uk/learn)
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Source: [GradeNine](https://www.gradenine.co.uk/q/methane-ch-is-a-hydrocarbon-and-fa6e6619) · Published by Druglandscape Ltd.