Learning objective

Clarify that the mass number, or nucleon number, is the sum of protons and neutrons in an atom's nucleus.

Read the explanation, check the common trap, then practise with flashcards and questions.

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Exam focus

Read the explanation.
Check key terms.
Practise with linked questions.

Cambridge IGCSE ChemistryAtoms, elements and compoundsCore content

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Quick explanation

Clarify that the mass number, or nucleon number, is the sum of protons and neutrons in an atom's nucleus

This point belongs to Atomic structure and the Periodic Table, especially Atomic structure and the Periodic Table outcomes.
You need to be able to clarify that the mass number, or nucleon number, is the sum of protons and neutrons in an atom's nucleus.
The key ideas to know are Define.
Use the linked flashcards and practice questions to check recall, then practise applying the idea in an exam-style answer.

Key concepts

Define

Why it matters

This objective helps connect Atomic structure and the Periodic Table outcomes to exam-style questions, flashcards, and revision notes for Atomic structure and the Periodic Table.

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