# Iron has two common isotopes: iron-56 and iron-54. State what is meant by the term isotope and describe the differences in the subatomic particles found in an atom of iron-56 compared to an atom of iron-54.

> Eduqas A-Level Chemistry — 2.3 Transition metals (A-Level only) · State · 5 marks

> Iron is an element with atomic number 26. It has several naturally occurring isotopes, the most abundant being iron-56.

## Mark scheme (5 marks)

1. Isotopes are atoms of the same element with the same number of protons but a different number of neutrons.
2. Both iron-56 and iron-54 have the same number of protons (26 protons each).
3. Iron-56 has more neutrons than iron-54 (30 neutrons compared to 28 neutrons).
4. Both isotopes have the same number of electrons (26 electrons each), as the overall charge of an atom is zero.

## Key terms

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

## Related

- [Revision notes for Eduqas A-Level Chemistry](https://www.gradenine.co.uk/learn)
- [How to answer "State" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/iron-has-two-common-isotopes-iron-56-2b6971dd) · Published by Druglandscape Ltd.