This definitions covers Key Definitions within Atomic Structure for GCSE Physics. Revise Atomic Structure in Atomic Structure for GCSE Physics with 16 exam-style questions and 25 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 7 of 12 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
Topic position
Section 7 of 12
Practice
16 questions
Recall
25 flashcards
📖 Key Definitions
Atomic number (Z): The number of protons in the nucleus of an atom. This defines the element.
Mass number (A): The total number of protons and neutrons (nucleons) in the nucleus.
Isotopes: Atoms of the same element with the same number of protons but different numbers of neutrons.
Nucleon: A particle found in the nucleus — either a proton or a neutron.
Ion: An atom that has lost or gained electrons, giving it an overall electric charge.
Keep building this topic
Read this section alongside the surrounding pages in Atomic Structure. That gives you the full topic sequence instead of a single isolated revision point.
Practice Questions for Atomic Structure
What does the atomic number of an element tell you?
Describe the structure of an atom. Include the location and charge of the three main subatomic particles.
Quick Recall Flashcards
16 questions on Atomic Structure — practise free
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