2 (a) The thermal decomposition of calcium carbonate makes calcium oxide and carbon dioxide. (i) Write the word equation for the thermal decomposition of calcium carbonate. + [1] (ii) The production of lime (calcium oxide) from limestone (calcium carbonate) is one use of limestone. State one other use of limestone. … [1] (iii) Calcium carbonate has the formula CaCO3. State the number of different elements present in calcium carbonate. … [1] (iv) Explain why the thermal decomposition of calcium carbonate is a chemical change and not a physical change. … … [1] (v) The thermal decomposition of calcium carbonate is an endothermic reaction. State what is meant by an endothermic reaction. … … … [1] (b) (i) Carbon dioxide is a compound but carbon is an element. State the difference between an element and a compound. … … … [2] (ii) Carbon is a solid and carbon dioxide is a gas. Complete Table 2.1 to describe the differences between a solid and a gas. One difference has been done for you. Table 2.1 particle separation particle arrangement particle motion solid vibrate about a fixed point gas move rapidly in all directions [2] (c) Carbon exists in many forms including diamond and graphite. Diamond and graphite are described as giant covalent structures. Fig. 2.1 shows three covalent structures, A, B and C. A B C carbon atom Fig. 2.1 (i) State which structure represents diamond. Choose from A, B or C. … [1] (ii) State which structure represents graphite. Choose from A, B or C. … [1] (iii) State why the bonding between the carbon atoms in diamond is covalent and not ionic. … … [1] [Total: 12]

2(a)(i) calcium carbonate → calcium oxide + carbon dioxide ; 1 2(a)(ii) neutralizing acidic soil / building material / cement ; 1 2(a)(iii) 3 ; 1 2(a)(iv) new substances produced ; 1 2(a)(v) (thermal) energy taken in ; 1 2(b)(i) an element contains only one type of atom ; a compound contains two or more elements chemically combined ; 2 2(b)(ii) particles separation particle arrangement particle motion solid close together regular vibrate about a fixed point gas far apart random move rapidly in all directions particle separation column ; particle arrangement column ; 2 2(c)(i) A ; 1 2(c)(ii) B ; 1 2(c)(iii) 2 non-metal atoms bonding / electrons are shared ; 1 (a)(i) To earn this mark, you must write the correct word equation for the thermal decomposition of calcium carbonate, including the arrow and plus signs. (a)(ii) You need to state any one valid use of limestone, such as neutralizing acidic soil, as a building material, or for cement. (a)(iii) To get this mark, you must correctly identify the number of different elements present in the formula CaCO3. (a)(iv) You earn this mark by explaining that new substances are produced during the thermal decomposition. (a)(v) This mark is awarded for stating that an endothermic reaction involves the taking in of thermal energy. (b)(i) You must define an element as containing only one type of atom and a compound as containing two or more elements chemically combined. (b)(ii) You need to correctly fill in the 'particle separation' and 'particle arrangement' columns for both solid and gas, showing close together/regular for solid and far apart/random for gas. (c)(i) You must select option A. (c)(ii) You must select option B. (c)(iii) You need to explain that covalent bonding involves two non-metal atoms bonding or that electrons are shared.

5 (a) Potassium is a very reactive metal. Potassium is stored under oil as shown in Fig. 5.1. potassium oil pieces of potassium Fig. 5.1 Suggest two reasons why potassium is stored under oil. 1 … 2 … [2] (b) Potassium has a proton number of 19. Complete Fig. 5.2 to show the electronic structure of a potassium atom. The inner shell electrons have been drawn for you. Fig. 5.2 [2] (c) Solid potassium reacts with chlorine gas to make solid potassium chloride. (i) Describe the differences between the structures of a solid and a gas in terms of particle separation and particle arrangement. particle separation … … particle arrangement … … [2] (ii) When potassium reacts with chlorine, potassium atoms become potassium ions. Describe what happens to a potassium atom when it becomes a potassium ion. … [1] (iii) Potassium and chlorine are elements. Potassium chloride is a compound. Describe the difference between an element and a compound. … … … [2] (d) The maximum mass of potassium chloride that dissolves in 100 cm3 of water is called the solubility of potassium chloride. Fig. 5.3 shows the solubility of potassium chloride in water at different temperatures. 0 10 20 30 40 50 60 70 10 20 30 40 50 temperature / °C solubility g / 100 cm3 of water 60 70 80 90 100 Fig. 5.3 (i) Describe the trend in solubility shown in Fig. 5.3. … [1] (ii) State the mass of potassium chloride that dissolves in 100 cm3 of water at 45 °C. …g [1] [Total: 11]

5(a) to prevent potassium reacting (with) ; air / oxygen / water vapour ; 2 5(b) 19 electrons shown ; (2).8.8.1 ; 2 5(c)(i) particle separation - further apart in a gas / touching / close in a solid) ; particle arrangement – regular arrangement in solid / random arrangement in gas ; 2 5(c)(ii) loses one electron ; 1 5(c)(iii) an element contains only one type of atom ; a compound contains two or more elements / different atoms chemically combined ; 2 5(d)(i) solubility increases as temperature rises ; 1 5(d)(ii) 41 g ; (± 1) 1 (a) To earn these two marks, you must state that potassium is stored under oil to prevent it from reacting with 'air / oxygen / water vapour'. (b) To earn these two marks, you must show 19 electrons in total and correctly draw the electronic structure as (2).8.8.1. (c)(i) To earn these two marks, you must describe particle separation as 'further apart in a gas / touching / close in a solid' and particle arrangement as 'regular arrangement in solid / random arrangement in gas'. (c)(ii) To earn this mark, you must state that potassium atoms 'lose one electron' to become potassium ions. (c)(iii) To earn these two marks, you must define an element as containing 'only one type of atom' and a compound as containing 'two or more elements / different atoms chemically combined'. (d)(i) To earn this mark, you must state that 'solubility increases as temperature rises'. (d)(ii) To earn this mark, you must correctly read the value '41 g' (within ±1) from the graph.

5 (a) Potassium is a very reactive metal. Potassium is stored under oil as shown in Fig. 5.1. potassium oil pieces of potassium Fig. 5.1 Suggest two reasons why potassium is stored under oil. 1 … 2 … [2] (b) Potassium has a proton number of 19. Complete Fig. 5.2 to show the electronic structure of a potassium atom. The inner shell electrons have been drawn for you. Fig. 5.2 [2] (c) Solid potassium reacts with chlorine gas to make solid potassium chloride. (i) Describe the differences between the structures of a solid and a gas in terms of particle separation and particle arrangement. particle separation … … particle arrangement … … [2] (ii) When potassium reacts with chlorine, potassium atoms become potassium ions. Describe what happens to a potassium atom when it becomes a potassium ion. … [1] (iii) Potassium and chlorine are elements. Potassium chloride is a compound. Describe the difference between an element and a compound. … … … [2] (d) The maximum mass of potassium chloride that dissolves in 100 cm3 of water is called the solubility of potassium chloride. Fig. 5.3 shows the solubility of potassium chloride in water at different temperatures. 0 10 20 30 40 50 60 70 10 20 30 40 50 temperature / °C solubility g / 100 cm3 of water 60 70 80 90 100 Fig. 5.3 (i) Describe the trend in solubility shown in Fig. 5.3. … [1] (ii) State the mass of potassium chloride that dissolves in 100 cm3 of water at 45 °C. …g [1] [Total: 11]

5(a) to prevent potassium reacting (with) ; air / oxygen / water vapour ; 2 5(b) 19 electrons shown ; (2).8.8.1 ; 2 5(c)(i) particle separation - further apart in a gas / touching / close in a solid) ; particle arrangement – regular arrangement in solid / random arrangement in gas ; 2 5(c)(ii) loses one electron ; 1 5(c)(iii) an element contains only one type of atom ; a compound contains two or more elements / different atoms chemically combined ; 2 5(d)(i) solubility increases as temperature rises ; 1 5(d)(ii) 41 g ; (± 1) 1 (a) To earn these two marks, you must state that potassium is stored under oil to prevent it from reacting with 'air / oxygen' and 'water vapour'. (b) To earn these two marks, you must show 19 electrons in total and correctly draw the electronic structure as 2.8.8.1. (c)(i) To earn these two marks, you must describe particle separation as 'further apart in a gas / touching / close in a solid' and particle arrangement as 'regular arrangement in solid / random arrangement in gas'. (c)(ii) To earn this mark, you must state that a potassium atom 'loses one electron' to become an ion. (c)(iii) To earn these two marks, you must define an element as containing 'only one type of atom' and a compound as containing 'two or more elements / different atoms chemically combined'. (d)(i) To earn this mark, you must state that 'solubility increases as temperature rises'. (d)(ii) To earn this mark, you must correctly read the value '41 g' (within ±1) from the graph.

11 (a) Fig. 11.1 shows iron rusting. rust Fig. 11.1 (i) Iron rusts when two other substances are present. State the names of these two substances. … and … [2] (ii) Describe and explain one method used to prevent the rusting of iron. … … … [2] (b) Stainless steel is an alloy of iron. State one use for stainless steel. … [1] (c) Solid iron melts at 1538 °C to become liquid (molten) iron. Describe one difference in the properties of a solid compared to a liquid. … … [1] (d) Melting is one of the processes involved when a substance changes state. Fig. 11.2 shows other processes involved when substances change state. solid liquid gas m e lt i n g C A B Fig. 11.2 Identify processes A, B and C. A … B … C … [3] [Total: 9]

11(a)(i) oxygen ; water ; 2 11(a)(ii) painting / greasing / electroplating ; provides a barrier etc ; 2 11(b) cutlery ; 1 11(c) solid has a definite shape / liquid takes up shape of container ; 1 11(d) A boiling ; B condensing ; C freezing ; 3

Cambridge IGCSE Co-ordinated Sciences · 0654

IGCSE Co-ordinated Sciences (0654) States of matter past paper questions

Revise IGCSE Co-ordinated Sciences (0654) — States of matter with real Cambridge past-paper questions grouped by topic, each shown with its marking scheme. Working one topic at a time targets exactly the skill each question tests.

33 free questions from 2016–2021, each with its marking scheme. Open the full topical bank to filter by subtopic, paper, and year.

States of matter in IGCSE Co-ordinated Sciences 0654 exams, 2020–2025

Across 2020–2025, States of matter accounted for 61 questions worth 456 marks in Cambridge IGCSE Co-ordinated Sciences (0654) papers.

By year
Year	Questions	Marks
2020	7	69
2021	11	105
2022	8	35
2023	6	40
2024	13	94
2025	16	113

Most-tested subtopics

C1.1 Solids, liquids and gases379 marks
C1.2 Diffusion91 marks

Appears in

Paper 1 · 7 qs
Paper 2 · 11 qs
Paper 3 · 22 qs
Paper 4 · 13 qs
Paper 5 · 2 qs
Paper 6 · 6 qs

All most-tested Co-ordinated Sciences topics

2021 Oct/Nov · Paper 3 · Q2 · 12 marks
Marking scheme
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2021 May/Jun · Paper 3 · Q5 · 11 marks
Marking scheme
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2021 May/Jun · Paper 3 · Q5 · 11 marks
Marking scheme
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2021 May/Jun · Paper 3 · Q11 · 9 marks
Marking scheme
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2021 Oct/Nov · Paper 2 · Q32 · 1 mark
Marking scheme
Mark scheme — 2021 Paper 2 Q32
Answer: A
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