Cambridge IGCSE · 0620 · Paper 3 · Theory (Core)

Chemistry 0620/31 Oct/Nov 2025 past paper

Cambridge IGCSE Chemistry (0620) Paper 3 (Theory (Core)), variant 1, Oct/Nov 2025: the question paper and its official mark scheme, 8 questions worth 80 marks, with the grade thresholds. Free to open, no account needed.

Questions: 8
Marks: 80
Grade A from: 41

Open the question paper Mark scheme

File names: 0620_w25_qp_31 · 0620_w25_ms_31

Grade thresholds for 0620/31 Oct/Nov 2025

The minimum raw marks Cambridge set for each grade on this component (out of 80). Thresholds change every session and variant, so always compare your score with the paper you actually sat.

A	B	C	D	E
41	35	28	21	14

Topics in this paper

Which syllabus chapters 0620/31 Oct/Nov 2025 tested, by marks. Each chapter links to every past-paper question on it.

Chapter	Questions	Marks
Stoichiometry	3	30
The Periodic Table	2	21
Metals	1	12
Electrochemistry	1	11
Atoms, elements and compounds	1	6

Questions in 0620/31 Oct/Nov 2025

Question 1The Periodic Table · 5 marks
Fig. 1.1 shows part of the Periodic Table. S Si Fe Ti Zn Cu Mg K Li I II III IV V VI VII VIII Cl Al …
Question 2Atoms, elements and compounds · 6 marks
The symbol for an atom of argon is shown. 18 40 Ar (a) Complete Table 2.1 to show the number of protons and neutrons in one atom of 18 40 Ar. Table 2.1 number of protons number of neutrons (b) …
Question 3Stoichiometry · 9 marks
(a) Table 3.1 shows the masses of ions, in mg, present in a 1000 cm3 sample of river water. Table 3.1 name of ion formula of ion mass of ion in 1000 cm3 of river water / mg ammonium NH4 …
Question 4Stoichiometry · 16 marks
(a) Molecules of compound C are produced by some plants. Fig. 4.1 shows the displayed formula of a molecule of compound …
Question 5The Periodic Table · 16 marks
This question is about elements in Group I and in Group VII of the Periodic Table and their compounds. (a) Chlorine is in Group VII of the Periodic Table. Give the colour and state of chlorine at room temperature and …
Question 6Metals · 12 marks
This question is about metals. (a) Iron is extracted from its ore using carbon (coke) and calcium carbonate in a blast furnace. (i) Give two reasons why carbon is used in a blast furnace. 1 2 (ii) Slag is a …
Question 7Electrochemistry · 11 marks
Fig. 7.1 shows the apparatus used to electrolyse dilute sulfuric acid using inert electrodes. power supply + – dilute sulfuric acid Fig. 7.1 (a) State what is meant by the term electrolysis. (b) Label the cathode in Fig. 7.1. (c) …
Question 8Stoichiometry · 5 marks
A student investigates the reaction of small pieces of magnesium with excess dilute hydrochloric acid. Mg + 2HCl MgCl …

Other Chemistry papers from Oct/Nov 2025

Questions students ask

Where can I get the 0620/31 Oct/Nov 2025 mark scheme?

Open the mark scheme above - it is the official Cambridge scheme for this exact paper (0620_w25_ms_31), and on a wide screen it sits beside the question you are reading.

What was the grade threshold for an A in 0620/31 Oct/Nov 2025?

41 marks out of 80, a C needed 28.

Which topics came up in 0620/31 Oct/Nov 2025?

Mostly Stoichiometry, The Periodic Table, Metals. The full list is in the table above.

Do I need an account to open 0620/31 Oct/Nov 2025?

No. Every paper opens for free without signing in. A free account also saves your pen marks and records your score against the grade thresholds.