Exercise 1 — IGCSE 0653 Mar 2024 Paper 32 Q2
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loss of one electron (from its outer shell)
Cambridge IGCSE·Combined Sciences 0653·Chemistry
Atoms Elements Compounds
Key knowledge — Atoms Elements Compounds
Formulas & equations
Mass number = protons + neutronsAtomic number = number of protons = number of electrons (neutral atom)
Key facts & rules
- Protons: +1 charge, in nucleus. Neutrons: neutral, in nucleus. Electrons: −1 charge, in shells.
- Isotopes: same element (same proton number), different mass number (different neutrons). Same chemical properties.
- Electronic configuration: fill shells 2, 8, 8, 18 … (first shell max 2, second max 8).
- Group number = number of outer electrons. Period number = number of occupied shells.
- Ion: atom that has gained or lost electrons. Cation (+): lost electrons. Anion (−): gained electrons.
- Relative atomic mass (Ar): weighted average mass of an atom compared to 1/12 of ¹²C.
- Compound: two or more elements chemically bonded — fixed ratio, different properties from elements.
- Mixture: can be separated by physical means (filtration, distillation, chromatography).
IGCSE Chemistry — Atoms, Elements & Compounds
8 Cambridge IGCSE 0653 Combined Sciences past paper questions on atoms, elements & compounds, across Theory, Multiple Choice and Alternative to Practical.
About Atoms, Elements & Compounds on IGCSE 0653
All matter is made of atoms. Atoms contain protons, neutrons and electrons. Elements consist of one type of atom; compounds contain two or more elements chemically joined; mixtures can be separated by physical means.
What's covered:
- Protons, neutrons and electrons
- Atomic number and mass number
- Isotopes
- Ions: cations and anions
- Elements, compounds and mixtures
- Symbols and formulae
Theory
Atoms, Elements & Compounds — Core1 · Paper 3
Atoms, Elements & Compounds — Extended2 · Paper 4
Exercise 1 — IGCSE 0653 May/Jun 2023 Paper 43 Q5
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(solute) ammonium nitrate
Exercise 2 — IGCSE 0653 May/Jun 2025 Paper 42 Q8
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variable resistor
Multiple choice
Atoms, Elements & Compounds — Extended MCQ3 · Paper 2
Question 1 — IGCSE 0653 May/Jun 2023 Paper 21 Q14
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Correct answer: D
Question 2 — IGCSE 0653 May/Jun 2023 Paper 21 Q15
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Correct answer: D
Question 3 — IGCSE 0653 May/Jun 2023 Paper 21 Q16
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Correct answer: B
Alternative to practical
Atoms, Elements & Compounds — ATP2 questions
Exercise 1 — IGCSE 0653 May/Jun 2025 Paper 52 Q2
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initial temperature recorded to 0.5 °C
Exercise 2 — IGCSE 0653 May/Jun 2025 Paper 62 Q2
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21.5
All Atoms, Elements & Compounds questions in this collection
| Type | Level | Paper | Session | Q# | Marks | Answer / key |
|---|---|---|---|---|---|---|
| ATP | Core | Paper 52 | May/Jun 2025 | Q2 | 13 marks | initial temperature recorded to 0.5 °C |
| ATP | Extended | Paper 62 | May/Jun 2025 | Q2 | 13 marks | 21.5 |
| MCQ | Extended | Paper 21 | May/Jun 2023 | Q14 | 1 mark | D |
| MCQ | Extended | Paper 21 | May/Jun 2023 | Q15 | 1 mark | D |
| MCQ | Extended | Paper 21 | May/Jun 2023 | Q16 | 1 mark | B |
| Theory | Core | Paper 32 | Mar 2024 | Q2 | 9 marks | loss of one electron (from its outer shell) |
| Theory | Extended | Paper 43 | May/Jun 2023 | Q5 | 9 marks | (solute) ammonium nitrate |
| Theory | Extended | Paper 42 | May/Jun 2025 | Q8 | 7 marks | variable resistor |