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Atom - GCSE Physics Definition

Reviewed by: Philippa Platt

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An atom is the basic unit of matter, consisting of a central nucleus surrounded by electrons. The nucleus contains positively charged protons and neutrally charged neutrons, while electrons, which are negatively charged, orbit the nucleus in electron shells.

Atoms are incredibly small, typically around 0.1 nanometres in diameter, and they are the fundamental building blocks of all substances.

Different types of atoms, known as elements, have varying numbers of protons, which define the element's identity in the periodic table. Understanding atoms is essential in GCSE Physics as they explain the composition and behaviour of matter in the universe.

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Philippa Platt

Reviewer: Philippa Platt

Expertise: Chemistry Content Creator

Philippa has worked as a GCSE and A level chemistry teacher and tutor for over thirteen years. She studied chemistry and sport science at Loughborough University graduating in 2007 having also completed her PGCE in science. Throughout her time as a teacher she was incharge of a boarding house for five years and coached many teams in a variety of sports. When not producing resources with the chemistry team, Philippa enjoys being active outside with her young family and is a very keen gardener

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