The nuclear model of the atom — Paper 2 · IGCSE Physics (9-1) 0972

37 In the atomic model, an atom consists of a central mass, orbited by much smaller particles. orbiting central particle mass What is the name of the central mass and of the orbiting particles? central mass orbiting particles A neutron α-particles B neutron electrons C nucleus α-particles D nucleus electrons

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Answer: D

This question in 0972/21 May/June 2018

38 Nuclear fusion is a reaction that takes place in stars. Which row describes this reaction? action of atomic nuclei energy A an atomic nucleus splits into absorbed two or more smaller nuclei B an atomic nucleus splits into released two or more smaller nuclei C atomic nuclei join together absorbed to form a larger nucleus D atomic nuclei join together released to form a larger nucleus

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Answer: D

This question in 0972/21 May/June 2018

37 Which diagram represents the structure of a neutral atom? A B C D key – – – – neutron + proton + + + + + + + + – electron – – –

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Answer: B

This question in 0972/21 Oct/Nov 2018

38 When a uranium-235 nucleus absorbs a neutron, it becomes unstable and undergoes fission. The fission process produces a barium (Ba) nucleus, a krypton (Kr) nucleus and 3 neutrons. The fission process is represented by the nuclear equation shown. 1 n + 235 U → 144 Ba + Kr ... + 3 n 1 0 92 56 ... 0 Which symbol represents the resulting krypton nucleus? A 89 Kr B 91 Kr C 91 Kr D 91 Kr 36 34 35 36

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Answer: A

This question in 0972/21 Oct/Nov 2018

38 The chemical symbol for sodium is Na. The equation represents the radioactive decay of sodium-24. 24Na → 24Mg + ye 11 x –1 What are the numbers x and y? x y A 10 0 B 10 1 C 12 0 D 12 1

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Answer: C

This question in 0972/21 May/June 2019

38 Which observation provides evidence for the nuclear atom? A attraction of opposite charges B emission of γ-rays during the decay of a radioactive nuclide C scattering of α-particles by thin metal foils D scattering of γ-rays by a thin metal foil

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Answer: C

This question in 0972/22 May/June 2019

39 The chemical symbol for uranium is U. The equation represents the radioactive decay of uranium-235. 235U → xTh + 4He 92 y 2 What are the numbers x and y? x y A 231 94 B 231 90 C 239 94 D 239 90

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Answer: B

This question in 0972/22 May/June 2019

27 A plastic rod is rubbed with a dry cloth. The rod becomes positively charged. Why has the rod become positively charged? A It has gained electrons. B It has gained neutrons. C It has lost electrons. D It has lost neutrons.

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Answer: C

This question in 0972/21 Oct/Nov 2019

37 Which diagram shows a possible structure of a neutral atom? A B key proton neutron electron C D

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Answer: A

This question in 0972/21 Oct/Nov 2019

38 The scattering of particles by a thin gold foil provided scientists with evidence for the nuclear atom. Which particles were scattered by the gold nuclei in the thin foil? A α-particles B β-particles C neutrons D protons

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Answer: A

This question in 0972/21 Oct/Nov 2019

37 Uranium-235 is a radioactive isotope. It undergoes a chain of decays and eventually forms the stable isotope lead-207. These two isotopes are represented as shown. 235U 207Pb 92 82 During this chain of decay, how many protons and how many neutrons are lost from a single nucleus of uranium-235 to form a single nucleus of lead-207? protons neutrons A 10 18 B 10 28 C 18 10 D 28 10

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Answer: A

This question in 0972/21 May/June 2020

40 α-particles, β-particles and γ-rays are emitted by radioactive nuclei when they decay. Which emissions can be deflected by an electric field? A α-particles and β-particles only B β-particles and γ-rays only C γ-rays and α-particles only D α-particles, β-particles and γ-rays

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Answer: A

This question in 0972/21 May/June 2020

28 A cloth is used to rub an uncharged plastic rod. Both the rod and the cloth become charged. Why does the plastic rod become negatively charged and the cloth become positively charged? A The rod gains electrons and the cloth gains positive charges. B The rod gains electrons and the cloth loses electrons. C The rod loses electrons and the cloth gains electrons. D The rod loses electrons and the cloth loses positive charges.

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Answer: B

This question in 0972/22 May/June 2020

37 Uranium-235 can undergo nuclear fission in many ways. Which equation correctly shows a possible fission reaction for uranium-235? 1n 235U 141Ba 92Kr 31n A + → + + 0 92 56 36 0 1n 235U 91Sr 144Xe 21n B + → + + 0 92 38 54 0 1n 235U 95Rb 136Cs 31n C + → + + 0 92 37 55 0 1n 235U 87Br 146La 41n D + → + + 0 92 35 57 0

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Answer: A

This question in 0972/22 May/June 2020

38 Which statement is correct for the nucleus of any atom? A The nucleus contains electrons, neutrons and protons. B The nucleus contains the same number of protons as neutrons. C The nucleus has a total charge of zero. D The nucleus is very small compared with the size of the atom.

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Answer: D

This question in 0972/21 Oct/Nov 2020

40 Which equation represents the B-decay of lead-209? A B “ePb + Se > “3,8 “ePb + Je 5 Tl “aePb > “3,Bi + Je oe 2P b > onl 1 + Je

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Answer: C

This question in 0972/21 Oct/Nov 2020

8 Electrical energy may be obtained from nuclear fission. In which order is the energy transferred in this process? A nuclear fuel  generator  reactor and boiler  turbines B nuclear fuel  generator  turbines  reactor and boiler C nuclear fuel  reactor and boiler  generator  turbines D nuclear fuel  reactor and boiler  turbines  generator

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Answer: D

This question in 0972/21 Oct/Nov 2021

37 The nucleus of an americium atom contains 146 neutrons and 95 protons. It decays by emitting an -particle. How many neutrons and how many protons remain in the nucleus when this form of americium decays? number of neutrons number of protons remaining remaining A 142 93 B 142 95 C 144 93 D 144 95

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Answer: C

This question in 0972/21 Oct/Nov 2021

38 How do the sizes of the two nuclei produced in a nuclear fission reaction compare to the size of the original nucleus? A both larger than the original nucleus B one larger and one smaller than the original nucleus C both smaller than the original nucleus D one smaller and one the same size as the original nucleus

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Answer: C

This question in 0972/21 May/June 2022

38 A scientist was asked to separate the following equations into two categories: nuclear fission and nuclear fusion. 1 239 Pu  112 Pd + 124 Cd + 31 n 94 46 48 0 2 3 He + He 3  He 4 + H 1 + H 1 2 2 2 1 1 3 14 N + H 1  15 O 7 1 8 4 235 U  90 Kr + 143 Ba + 21 n 92 36 56 0 Which equations show nuclear fission? A 1 and 2 B 1 and 3 C 1 and 4 D 2 and 4

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Answer: C

This question in 0972/22 May/June 2022

37 A very important experiment increased scientists’ understanding of the structure of matter. In the experiment, particles scattered as they passed through a thin metal foil. Which particles were used, and to which conclusion did the experiment lead? particles conclusion A alpha-particles matter is made up of atoms B alpha-particles atoms have a very small nucleus C beta-particles matter is made up of atoms D beta-particles atoms have a very small nucleus

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Answer: B

This question in 0972/21 Oct/Nov 2022

38 Polonium, Po, has a proton number equal to 84 and a nucleon number equal to 218. Polonium changes into astatine, At, by emitting a β-particle. Which equation represents this decay? 84 Po 8 5 At –1 β A → + 218 218 0 84 Po –1 β 8 5 At B + → 218 0 218 218 Po 218 At 0 β C → + 8 4 85 – 1 218 Po 0 β 218 At D + → 8 4 – 1 85

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Answer: C

This question in 0972/21 Oct/Nov 2022

40 What is the nature of α-emission? A electromagnetic waves B negatively charged particles C positively charged particles D uncharged particles

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Answer: C

This question in 0972/21 Oct/Nov 2022

33 How are positive and negative ions formed from atoms? positive ion negative ion A add positive charge to the nucleus add an electron to the atom B add positive charge to the nucleus remove positive charge from the nucleus C remove an electron from the atom add an electron to the atom D remove an electron from the atom remove positive charge from the nucleus 56 26X

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Answer: C

This question in 0972/21 May/June 2023

34 A nucleus of element X is represented as . Which is an isotope of element X? 26 X 54 X 56 X 54 X A B C D 56 26 24 28

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Answer: B

This question in 0972/21 May/June 2023

39 Which nuclear reaction powers a stable star? A nuclear fission of nuclei producing hydrogen B nuclear fission of a uranium nucleus into a krypton nucleus and a barium nucleus C nuclear fusion of a krypton nucleus and a barium nucleus into a uranium nucleus D nuclear fusion of hydrogen nuclei producing helium

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Answer: D

This question in 0972/21 May/June 2023

24 A plastic rod is rubbed with a dry cloth. The rod becomes positively charged. Why has the rod become positively charged? A It has gained electrons. B It has gained neutrons. C It has lost electrons. D It has lost neutrons.

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Answer: C

This question in 0972/22 May/June 2023

33 Fission and fusion are two types of nuclear process. How does the total mass of the nuclides produced compare with the total mass of the original nuclide or nuclides in these nuclear processes? total mass of fission total mass of fusion products compared products compared to original nuclide to original nuclides A same same B more less C less more D less less

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Answer: D

This question in 0972/22 May/June 2023

34 The table shows the composition of three different nuclei. number of number of nucleus protons neutrons X 3 3 Y 3 4 Z 4 3 Which nuclei are isotopes of the same element? A X, Y and Z B X and Y only C X and Z only D Y and Z only

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Answer: B

This question in 0972/22 May/June 2023

35 Which change occurs in the nucleus of a radioactive atom during -emission? A A neutron transforms into a proton and an electron. B A neutron transforms into a proton only. C A proton transforms into a neutron and an electron. D A proton transforms into a neutron only.

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Answer: A

This question in 0972/22 May/June 2023

39 Which nuclear reaction produces the release of energy to power a star? A nuclear fission of helium into hydrogen B nuclear fission of hydrogen into helium C nuclear fusion of helium into hydrogen D nuclear fusion of hydrogen into helium

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Answer: D

This question in 0972/22 May/June 2023

34 In -particle scattering, -particles are incident on a thin metal foil. Which row describes results from the experiment and a conclusion that the results lead to? results conclusion A most of the -particles most of the atom is empty space pass straight through the foil B most of the -particles the nucleus is very large pass straight through the foil C very few of the -particles most of the atom is empty space pass straight through the foil D very few of the -particles the nucleus is very large pass straight through the foil

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Answer: A

This question in 0972/21 Oct/Nov 2023

37 Which particle is absorbed by a nucleus to cause nuclear fission? A a neutron B a proton C an -particle D a -particle

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Answer: A

This question in 0972/21 Oct/Nov 2023

32 A scientist fires alpha-particles at a very thin sheet of gold and detects the particles that pass through. Which statement about the results of the scattering experiment is correct? A Alpha-particles are attracted to the nucleus of the atoms in the metal sheet. B Half the mass of the atom is concentrated in the nucleus. C Most of the alpha-particles are deflected, showing that the nucleus is very dense. D Only a small number of alpha-particles are deflected, but some of these are deflected through large angles.

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Answer: D

This question in 0972/21 May/June 2024

33 The notation represents the nucleus of a gold atom. 197Au 79 The relative charge on a proton is +1. What is the relative charge on the gold nucleus? A +79 B +118 C +197 D +276

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Answer: A

This question in 0972/21 May/June 2024

34 An isotope of hydrogen has the nuclide notation H. 2 1 How many neutrons are in the nucleus of this isotope and what is the relative charge on the nucleus? number of relative neutrons charge A 1 +1 B 1 +2 C 2 +1 D 2 +2

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Answer: A

This question in 0972/21 May/June 2024

38 What is the main process that powers the Sun? A burning of helium and oxygen B burning of hydrogen and oxygen C nuclear fusion of hydrogen to form helium D nuclear fission of helium to form hydrogen

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Answer: C

This question in 0972/21 May/June 2024

33 The scattering of particles by a thin gold foil provided scientists with evidence for the nuclear atom. Which particles were scattered by the gold nuclei in the thin foil? A -particles B -particles C neutrons D protons

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Answer: A

This question in 0972/22 May/June 2024

34 A nucleus X has 17 protons and 18 neutrons. Which notation is correct for this nucleus? A 17 X B 17 X C 18 X D 35 X 18 35 17 17

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Answer: D

This question in 0972/22 May/June 2024

8 Which statement about the use of nuclear fuel as an energy resource is correct? A It obtains its energy from the Sun. B It has no environmental impact. C Nuclear power stations do not need turbines. D The energy is released by nuclear fission.

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Answer: D

This question in 0972/21 Oct/Nov 2024

34 -particles are directed at a metal foil. Most of the particles pass through the foil with little change in direction. A small proportion of the particles are scattered back through large angles. What does this evidence suggest about the structure of an atom? A It consists of a charged centre much smaller than the size of the atom and with little of the mass of the atom. B It consists of a negative charge the size of the atom containing small positive charges scattered through it. C It consists of a charged centre much smaller than the size of the atom but with most of the mass of the atom. D It consists of a positive charge the size of the atom containing small negative charges scattered through it.

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Answer: C

This question in 0972/21 Oct/Nov 2024

36 Which statement about alpha decay is correct? A The nucleus loses electrons. B The nucleus changes to that of a different element. C The nucleus does not decay until after one half-life. D After two half-lives, alpha decay always stops.

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Answer: B

This question in 0972/21 Oct/Nov 2024

39 Which statement about the Sun is correct? A The nuclear reactions in the Sun create mainly radio waves and microwaves. B The Sun is powered by fission reactions in which hydrogen is converted into helium. C The Sun is powered by fission reactions in which lithium is converted into helium. D The Sun is powered by fusion reactions and electromagnetic radiation is produced.

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Answer: D

This question in 0972/21 Oct/Nov 2024

33 In an alpha particle scattering experiment, a beam of alpha particles is fired at a very thin piece of gold foil. In which direction do most of the alpha particles travel after hitting the foil? gold foil beam of alpha particles A D B C

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Answer: A

This question in 0972/21 May/June 2025

34 An atom of boron contains 5 protons and 5 electrons. The nucleon number of the atom is 11. How many neutrons are there in the atom? A 5 B 6 C 11 D 16

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Answer: B

This question in 0972/21 May/June 2025

36 Sodium-24 is a radioactive isotope that emits beta radiation. Which nuclear equation shows how sodium-24 decays? 4iNa > 42Mg + 5p “Na > *iNe + $B 24 20 4 Na — “oF + 5B 0 Oo WD > 24 20 4 1iNa — 43Al + 5B

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Answer: A

This question in 0972/21 May/June 2025

33 239 Pu is an isotope of plutonium. 94 The nucleus can absorb a neutron and then split to form two other nuclei. Two nuclei that form are gold, 207 Au, and phosphorus, 31 P. 79 15 In this reaction, neutrons are also produced. What is the number of neutrons produced when the nucleus splits? A 1 B 2 C 4 D 5

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Answer: B

This question in 0972/21 Oct/Nov 2025

34 Three statements about alpha () particles and beta () particles are listed. 1 The magnitude of the charge on an -particle is twice the charge on a -particle. 2 The mass of an -particle is large compared with the mass of a -particle. 3 The kinetic energy of an -particle is small compared to the kinetic energy of a -particle. Which statements help to explain the different ionising effects of -particles and -particles? A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

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Answer: B

This question in 0972/21 Oct/Nov 2025

35 A beta-particle is a fast-moving electron. Which statement explains how beta-particles are emitted from an atom? A An electron is emitted as a beta-particle from an inner electron shell of the atom. B An electron is emitted as a beta-particle from an outer electron shell of the atom. C A neutron changes into a proton and a beta-particle is emitted from the nucleus. D A proton changes into a neutron and a beta-particle is emitted from the nucleus.

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Answer: C

This question in 0972/21 Oct/Nov 2025