C1 Atomic Structure
Protons, neutrons, electrons, atomic and mass number, isotopes, ions and electronic structure.
How to study for CCEA GCSE Double Award Science
Build each scientific explanation from a model or relationship, show quantitative working, and connect every practical claim to controlled evidence and evaluation.
Core concepts
Concept 1
Atomic number gives proton number and mass number gives total protons plus neutrons.
Exam cue: Identify the scientific model, relationship or practical evidence required by the command word.
Concept 2
Atoms form ions by electron transfer while the nucleus remains unchanged in an ordinary chemical reaction.
Exam cue: For a particle calculation, write proton, neutron and electron counts separately and use charge to adjust electrons.
Concept 3
Electronic structure explains ion formation and connects an element's position to its chemical behaviour.
Exam cue: Use the current CCEA specification formatting and entered tier to decide whether Higher-only detail applies.
Risk pitfalls and guardrails
Changing proton number when explaining formation of a positive or negative ion.
Guardrail: Do not import another board or science route, omit units from a calculation, or make a scientific claim beyond the stated evidence.
Giving a remembered fact without connecting it to the stated data, observation or scenario.
Guardrail: Do not import another board or science route, omit units from a calculation, or make a scientific claim beyond the stated evidence.
Importing content or paper structure from a separate-science or non-CCEA specification.
Guardrail: Do not import another board or science route, omit units from a calculation, or make a scientific claim beyond the stated evidence.
Memory anchors
Atomic number
Number of protons in an atom's nucleus.
Mass number
Total number of protons and neutrons in a nucleus.
Isotope
Atoms of one element with different neutron numbers.
Ion
Charged particle formed by electron loss or gain.
Proton
Positively charged subatomic particle in the nucleus.
Electron shell
Energy level occupied by electrons around the nucleus.
Checkpoint rule
Do the check-up only after you can summarize each concept in one sentence and identify one dangerous pitfall from memory.
Knowledge Check (after reading)
Short check-up to confirm understanding of this module.
Check-up Questions
The identity of a chemical element is fixed by the number of which subatomic particle?
An atom has atomic number 17 and mass number 35. How many neutrons?
Answer all questions to submit.
Next step personalized recommendations
Continue learning
Move forward only after this module is stable.
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