# Alkanes and alkenes both belong to homologous series. Describe four features of a homologous series.

> Pearson Edexcel International GCSE Chemistry (4CH1) — 4.1 Introduction · Describe · 4 marks

## Mark scheme (4 marks)

1. Members of a homologous series share the same functional group / general formula
2. Members have similar chemical properties
3. Each successive member differs by one CH₂ unit
4. Physical properties (such as boiling point or viscosity) show a gradual trend / change gradually as the number of carbon atoms increases

## Key terms

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

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Source: [GradeNine](https://www.gradenine.co.uk/q/alkanes-and-alkenes-both-belong-to-9f5c5856) · Published by Druglandscape Ltd.