0653.C2.2.03 — Define proton number / atomic number as the number of protons in the nucleus of an atom: past paper questions
Real questions on 0653.c2.2.03 — define proton number / atomic number as the number of protons in the nucleus of an atom
The newest 20 of 21 written questions. Open one to see it on the real paper.
- 0653/43 · October/November 2025 · Q6a(i)[1]
Use Fig. 6.1 to deduce the molecular formula of pentene.
See it on the paper → - 0653/43 · October/November 2025 · Q6a(ii)[1]
The double carbon–carbon bond in pentene can be in different positions. C C C C C Complete Fig. 6.2 to show the structure of one other form of pentene.
See it on the paper → - 0653/43 · October/November 2025 · Q6a(iv)[2]
Draw lines to show which descriptions are true for pentene. One has been drawn for you. description is the main constituent of natural gas reacts with hydrogen in the presence of a nickel catalyst reacts with steam in the presence of an acid catalyst pentene is a saturated hydrocarbon decolourises aqueous bromine
See it on the paper → - 0653/42 · May/June 2025 · Q6e(ii)[1]
The structure of ethanol is shown in Fig. 6.1. H H H C C H H O (ii) H Fig. 6.1 Explain why ethanol is not a hydrocarbon.
See it on the paper → - 0653/32 · October/November 2024 · Q2a(i)[2]
+ + hydrogen Complete the word equation for this reaction.
See it on the paper → - 0653/32 · October/November 2024 · Q2a(ii)[2]
Describe the test for hydrogen gas. State the observation for the positive result. test
See it on the paper → - 0653/32 · October/November 2024 · Q2b(i)[1]
Table 2.2 shows the change in mass for three of the metals. Complete Table 2.2 by calculating the change in mass for zinc. Table 2.2 metal change in mass / g calcium 3.95 iron 1.40 magnesium 3.10 zinc (i)
See it on the paper → - 0653/32 · October/November 2024 · Q2b(ii)[2]
Use the information in Table 2.1 and Table 2.2 to identify the least reactive metal. Explain your answer. metal explanation
See it on the paper → - 0653/32 · October/November 2024 · Q2c(i)[2]
State two physical properties of iron.
See it on the paper → - 0653/32 · October/November 2024 · Q2c(ii)[1]
Iron is used to make alloys. Suggest why alloys are used instead of pure metals.
See it on the paper → - 0653/31 · October/November 2023 · Q2b(i)[1]
State the piece of apparatus used to measure the temperature of the boiling point of the aqueous sodium carbonate.
See it on the paper → - 0653/31 · October/November 2023 · Q2b(ii)[1]
State whether boiling is a chemical or a physical change. Give a reason for your answer. change reason
See it on the paper → - 0653/33 · October/November 2023 · Q5c(ii)[1]
Describe the colour change when aqueous bromine is added to an alkene. from to
See it on the paper → - 0653/43 · October/November 2022 · Q2b(i)[1]
Explain how Fig. 2.1 can be used to deduce the proton number of chlorine.
See it on the paper → - 0653/43 · October/November 2022 · Q2b(ii)[1]
Explain how Fig. 2.1 can be used to deduce the period number of chlorine in the Periodic Table.
See it on the paper → - 0653/22 · May/June 2022 · Q21[1]
Which row describes the electronic structure and character of indium?
See it on the paper → - 0653/22 · May/June 2022 · Q27[1]
Which substance rapidly turns aqueous bromine from orange to colourless?
See it on the paper → - 0653/42 · February/March 2022 · Q5a[2]
Describe the tests and positive results for hydrogen and for oxygen. test for hydrogen result test for oxygen result
See it on the paper → - 0653/42 · February/March 2022 · Q5b(i)[2]
Complete the ionic equations by adding in the missing state symbols.
See it on the paper → - 0653/42 · February/March 2022 · Q5b(ii)[2]
Explain the changes that happen at each electrode. Use ideas about electrons in your answer.
See it on the paper →
What examiners said
Most candidates noted the presence of oxygen in the structure of ethanol to explain why it is not a hydrocarbon.
— Examiner report, May/June 2025, 0653/42 Q6(e)(ii) (Cambridge)
The most important difference between a physical change and a chemical change is that there is no new substance made in the case of a physical change. Many candidates gained credit for stating this fact. Answers which were not acceptable included descriptions of the change of state, and any explanations stating that it must be a physical change because it can be seen happening.
— Examiner report, October/November 2023, 0653/31 Q2(b)(ii) (Cambridge)
Some candidates answered this correctly. Incorrect responses included those stating that the colour produced was clear instead of colourless. A clear solution may be coloured, and in the test for an alkene the bromine produces a colourless solution. Some candidates appeared to confuse bromine with iodine and the starch test because they wrote blue-black as one of the colours.
— Examiner report, October/November 2023, 0653/33 Q5(c)(ii) (Cambridge)
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