1 The diagram shows part of the Periodic Table. I II III IV V VI VII VIII Mg Al Ar Cl Br I C N O F Ca Cr Fe Cu Zn Pt K Answer the following questions using only the symbols of the elements in the diagram. Each symbol may be used once, more than once or not at all. Give the symbol of the element that: (a) is extracted from bauxite … [1] (b) forms 21% of clean, dry air … [1] (c) forms an oxide which contributes to acid rain … [1] (d) forms an aqueous ion that gives a red-brown precipitate on addition of aqueous sodium hydroxide … [1] (e) has an atom with a complete outer electron shell. … [1] [Total: 5]

1(a) Al 1 1(b) O 1 1(c) N 1 1(d) Fe 1 1(e) Ar 1 To earn the mark, you must correctly identify the specific element symbol for each description.

1 (a) The electronic structures of five atoms, A, B, C, D and E, are shown. A B C D E Answer the following questions about these electronic structures. Each electronic structure may be used once, more than once or not at all. State which electronic structure, A, B, C, D or E, represents: (i) an atom in Group II of the Periodic Table … [1] (ii) an atom with a proton number of 13 … [1] (iii) an atom that forms a stable ion with a single negative charge … [1] (iv) an atom of a non-metal that forms a giant covalent structure … [1] (v) an atom of a metal used in food containers. … [1] (b) Complete the table to show the number of electrons, neutrons and protons in the vanadium atom and calcium ion shown. number of electrons number of neutrons number of protons 51V 23 23 48Ca2+ 20 28 [3] [Total: 8]

1(a)(i) C 1 1(a)(ii) D 1 1(a)(iii) E 1 1(a)(iv) B 1 1(a)(v) D 1 1(b) number of electrons in Ca ion: = 18 (1) number of neutrons in V = 28 (1) number of protons in V = 23 AND number of protons in Ca ion = 20 (1) 3 (a) To earn marks, you must correctly identify the electronic structure (A, B, C, D, or E) that matches the given description for each sub-part. (b) To earn marks, you must correctly state the number of electrons in the Ca ion, the number of neutrons in V, and the number of protons for both V and the Ca ion.

1 (a) The electronic structures of five atoms, A, B, C, D and E, are shown. A B C D E Answer the following questions about these electronic structures. Each electronic structure may be used once, more than once or not at all. State which electronic structure, A, B, C, D or E, represents: (i) an atom in Group III of the Periodic Table … [1] (ii) an atom of a noble gas … [1] (iii) an atom that forms a stable ion with a single positive charge … [1] (iv) an atom that contains only two shells of electrons … [1] (v) an atom with a proton number of 16. … [1] (b) Complete the table to show the number of electrons, neutrons and protons in the silicon atom and sodium ion shown. number of electrons number of neutrons number of protons 30Si 14 14 23Na+ 11 12 [3] [Total: 8]

1(a)(i) B 1 1(a)(ii) D 1 1(a)(iii) A 1 1(a)(iv) B 1 1(a)(v) C 1 1(b) number of electrons in Na ion =10 (1) number of neutrons in Si = 16 (1) number of protons in Si = 14 AND number of protons in Na ion = 11 (1) 3 To earn marks, you must correctly identify the electronic structure (A, B, C, D, or E) for each description in part (a). For part (b), you need to provide the correct number of electrons for the Na+ ion, the correct number of neutrons for Si, and the correct number of protons for both Si and Na+.

1 (a) The electronic structures of five atoms, A, B, C, D and E, are shown. A B C D E Answer the following questions about these electronic structures. Each electronic structure may be used once, more than once or not at all. State which electronic structure, A, B, C, D or E, represents: (i) an atom of an element in Group VI of the Periodic Table … [1] (ii) an atom of a reactive metal … [1] (iii) an atom with a proton number of 17 … [1] (iv) an atom that forms a stable ion with a charge of 2– … [1] (v) an atom of oxygen. … [1] (b) Complete the table to show the number of electrons, neutrons and protons in the bromine atom and fluoride ion shown. number of electrons number of neutrons number of protons 81Br 35 35 19F– 9 10 [3] [Total: 8]

1(a)(i) D 1 1(a)(ii) E 1 1(a)(iii) B 1 1(a)(iv) D 1 1(a)(v) D 1 1(b) number of electrons in F ion = 10 (1) number of neutrons in Br = 46 (1) number of protons in Br = 35 AND number of protons in F ion = 9 (1) 3 (a) To earn marks, you must correctly identify the electronic structure (A, B, C, D, or E) that matches the given chemical property or atomic characteristic. (b) To earn marks, you must correctly state the number of electrons in the fluoride ion, the number of neutrons in the bromine atom, and both the number of protons in the bromine atom and the number of protons in the fluoride ion.

4 Element X has 7 protons. Element Y has 8 more protons than X. Which statement about element Y is correct? A Y has more electron shells than X. B Y has more electrons in its outer shell than X. C Y is in a different group of the Periodic Table from X. D Y is in the same period of the Periodic Table as X.

Answer: A The mark is earned by recognizing that adding 8 protons to element X (atomic number 7) results in an element (atomic number 15) that is in a different period, meaning it has more electron shells.

Cambridge IGCSE Chemistry · 0620

IGCSE Chemistry (0620) Atoms, elements and compounds past paper questions

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Atoms, elements and compounds in IGCSE Chemistry 0620 exams, 2020–2025

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2.4 Ions and ionic bonds1164 marks
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2021 Feb/Mar · Paper 3 · Q1 · 5 marks
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2021 May/Jun · Paper 1 · Q4 · 1 mark
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