# Explain why a perfect black body absorbs and emits radiation differently from a shiny metal surface.

> Eduqas GCSE Physics — 6.5 Black body radiation · Explain · 4 marks

> Scientists use the idea of a perfect black body to model how objects absorb and emit electromagnetic radiation. Real objects, such as shiny metal surfaces, behave differently from a perfect black body.

## Mark scheme (4 marks)

1. A perfect black body absorbs all incident radiation / no radiation is reflected or transmitted
2. A shiny metal surface reflects (most) radiation rather than absorbing it
3. A perfect black body is also the best possible emitter of radiation at any given temperature
4. The shiny metal surface emits less radiation than a perfect black body at the same temperature / is a poor emitter

## Key terms

- [black body](https://www.gradenine.co.uk/glossary/black-body)
- [absorb](https://www.gradenine.co.uk/glossary/absorb)
- [emit](https://www.gradenine.co.uk/glossary/emit)
- [radiation](https://www.gradenine.co.uk/glossary/radiation)

## Related

- [Revision notes for Eduqas GCSE Physics](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-a-perfect-black-body-204e104c) · Published by Druglandscape Ltd.