# Describe how scientists' understanding of atomic structure changed with the development of the nuclear model of the atom, and state one property of the nucleus.

> Eduqas GCSE Chemistry — C1 Atomic structure and the periodic table · Describe · 4 marks

> Early scientists believed that the atom was a solid sphere of positive charge with electrons embedded throughout it. Later experiments led to a new model being proposed.

## Mark scheme (4 marks)

1. The earlier (plum pudding / Thomson) model described the atom as a uniform / solid sphere of positive charge with electrons embedded in it
2. The nuclear model placed most of the positive charge / mass in a small central nucleus
3. Electrons orbit / are found around the outside / in shells around the nucleus
4. One correct property of the nucleus: it is very small / it is positively charged / it contains protons (and neutrons) / it contains most of the mass of the atom

## Key terms

- [nuclear model](https://www.gradenine.co.uk/glossary/nuclear-model)
- [nucleus](https://www.gradenine.co.uk/glossary/nucleus)

## Related

- [Revision notes for Eduqas GCSE Chemistry](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/describe-how-scientists-understanding-of-atomic-ea0c1b61) · Published by Druglandscape Ltd.