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IGCSE Physics: Radioactivity Exam Questions
With Correct Answers 100% Verified.
Radioactivity - Answer✔the emission of ionizing radiation or particles caused by the
spontaneous disintegration of atomic nuclei.
radioactivity unit - Answer✔Becquerel (Bq)
examples of radioactive material - Answer✔radium, uranium, radon and plutonium
structure of an atom - Answer✔nucleus made up of protons and neutrons; the electrons make
up the surrounding area
proton - Answer✔a subatomic particle that has a positive charge and that is found in the
nucleus of an atom
neutron - Answer✔a subatomic particle that has no charge and that is found in the nucleus of
an atom
electron - Answer✔a subatomic particle that has a negative charge
Why are atoms electrically neutral? - Answer✔So the opposite charges of protons and electrons
balance each other, producing a zero net charge. The atom is electrically neutral.
atomic number - Answer✔the number of protons in the nucleus of an atom
mass number - Answer✔the sum of the number of neutrons and protons in an atomic nucleus
Why are isotopes chemically alike? - Answer✔they have identical numbers of protons and
electrons
nucleon - Answer✔a proton or neutron
isotope - Answer✔each of two or more forms of the same element that contain equal numbers
of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic
mass but not in chemical properties; in particular, a radioactive form of an element.
1
, ©THESTAR 2024/2025 ALL RIGHTS RESERVED 11:09PM. A+
radiation - Answer✔energy that is radiated or transmitted in the form of rays or waves or
particles.
background radiation - Answer✔the nuclear radiation that arises naturally from cosmic rays
and from radioactive isotopes in the soil and air
activity - Answer✔the amount of radiation the material emits per second
where is radon present? - Answer✔air
where is uranium found? - Answer✔rocks
Geiger-Muller tube - Answer✔Device used to detect radiation using its ability to ionize matter
how is radiation emitted? - Answer✔randomly from the nucleus of unstable atoms that have
decayed.
describe the nature of alpha (α ) particles: - Answer✔relatively large particles, can travel only a
few cms in air, stopped by paper, are the same as a He atom, not very penetrating however
very ionising
describe the nature of beta (β) particles: - Answer✔small particles, can travel through paper,
stopped by aluminum a few mm thick, are electrons emitted when a neutron splits, fairly
penetrating and fairly ionising
describe the nature of gamma (γ) particles: - Answer✔very small (photons), can travel through
paper and aluminum, stopped partially by lead, are electromagnetic radiation with a very short
wavelength, very penetrating and not very ionising
alpha radiation - Answer✔a positively charged particle identical to a helium nucleus
radioactive decay - Answer✔a spontaneous process in which unstable nuclei lose energy by
emitting radiation
ionising radiation - Answer✔any form of radiation that has the ability to remove electrons from
atoms and molecules
Alpha radiation symbol - Answer✔4
He
2
beta radiation - Answer✔an electron from the nucleus after a neutron
beta radiation symbol - Answer✔0
e
2
IGCSE Physics: Radioactivity Exam Questions
With Correct Answers 100% Verified.
Radioactivity - Answer✔the emission of ionizing radiation or particles caused by the
spontaneous disintegration of atomic nuclei.
radioactivity unit - Answer✔Becquerel (Bq)
examples of radioactive material - Answer✔radium, uranium, radon and plutonium
structure of an atom - Answer✔nucleus made up of protons and neutrons; the electrons make
up the surrounding area
proton - Answer✔a subatomic particle that has a positive charge and that is found in the
nucleus of an atom
neutron - Answer✔a subatomic particle that has no charge and that is found in the nucleus of
an atom
electron - Answer✔a subatomic particle that has a negative charge
Why are atoms electrically neutral? - Answer✔So the opposite charges of protons and electrons
balance each other, producing a zero net charge. The atom is electrically neutral.
atomic number - Answer✔the number of protons in the nucleus of an atom
mass number - Answer✔the sum of the number of neutrons and protons in an atomic nucleus
Why are isotopes chemically alike? - Answer✔they have identical numbers of protons and
electrons
nucleon - Answer✔a proton or neutron
isotope - Answer✔each of two or more forms of the same element that contain equal numbers
of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic
mass but not in chemical properties; in particular, a radioactive form of an element.
1
, ©THESTAR 2024/2025 ALL RIGHTS RESERVED 11:09PM. A+
radiation - Answer✔energy that is radiated or transmitted in the form of rays or waves or
particles.
background radiation - Answer✔the nuclear radiation that arises naturally from cosmic rays
and from radioactive isotopes in the soil and air
activity - Answer✔the amount of radiation the material emits per second
where is radon present? - Answer✔air
where is uranium found? - Answer✔rocks
Geiger-Muller tube - Answer✔Device used to detect radiation using its ability to ionize matter
how is radiation emitted? - Answer✔randomly from the nucleus of unstable atoms that have
decayed.
describe the nature of alpha (α ) particles: - Answer✔relatively large particles, can travel only a
few cms in air, stopped by paper, are the same as a He atom, not very penetrating however
very ionising
describe the nature of beta (β) particles: - Answer✔small particles, can travel through paper,
stopped by aluminum a few mm thick, are electrons emitted when a neutron splits, fairly
penetrating and fairly ionising
describe the nature of gamma (γ) particles: - Answer✔very small (photons), can travel through
paper and aluminum, stopped partially by lead, are electromagnetic radiation with a very short
wavelength, very penetrating and not very ionising
alpha radiation - Answer✔a positively charged particle identical to a helium nucleus
radioactive decay - Answer✔a spontaneous process in which unstable nuclei lose energy by
emitting radiation
ionising radiation - Answer✔any form of radiation that has the ability to remove electrons from
atoms and molecules
Alpha radiation symbol - Answer✔4
He
2
beta radiation - Answer✔an electron from the nucleus after a neutron
beta radiation symbol - Answer✔0
e
2
