Question 1
Which particles make up the nucleus of an atom?
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Protons and neutrons
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Electrons and protons
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Neutrons and electrons
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Positrons and photons
Question 2
What does the atomic number Z represent?
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The number of protons in the nucleus
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The total number of neutrons and electrons
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The number of isotopes
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The number of energy levels
Question 3
For \(^{35}_{17}\text{Cl}\), how many neutrons are in the nucleus?
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\(18\)
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\(17\)
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\(35\)
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\(52\)
Question 4
Which pair of properties describes isotopes of one element?
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Same proton number; different neutron numbers
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Same neutron number; different proton numbers
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Same mass number; different proton numbers
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Different proton numbers; different electron shells
Question 5
Which type of radiation is a helium nucleus and carries \(+2\) charge?
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Alpha
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Beta
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Gamma
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X-ray
Question 6
Beta-minus radiation consists of which particles?
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High-speed electrons
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Protons
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Neutrons
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Alpha particles
Question 7
Which radiation is a high-energy photon and has no charge?
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Gamma
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Alpha
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Beta
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Neutron
Question 8
Place the types of radiation in order of increasing penetration through materials.
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Alpha, beta, gamma
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Gamma, beta, alpha
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Beta, alpha, gamma
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Alpha, gamma, beta
Question 9
Which radiation is most likely to be stopped by a sheet of paper?
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Alpha
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Gamma
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Beta
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Neutron
Question 10
Write the nuclear equation for the beta-minus decay of \(^{14}_6\text{C}\).
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\(^{14}_6\mathrm{C} \to ^{14}_7\mathrm{N} + ^{0}_{-1}\beta\)
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\(^{14}_6\mathrm{C} \to ^{13}_6\mathrm{C} + ^{1}_0\text{n}\)
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\(^{14}_6\mathrm{C} \to ^{14}_5\mathrm{B} + ^{1}_0\text{n}\)
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\(^{14}_6\mathrm{C} \to ^{13}_5\mathrm{B} + ^{0}_{-1}\beta\)
Question 11
What term describes the time for half of a radioactive sample to decay?
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Half-life
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Full life
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Decay constant
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Activity
Question 12
A sample has activity \(200\,\mathrm{Bq}\) and a half-life of \(2\,\mathrm{min}\). What is its activity after \(2\,\mathrm{min}\)?
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\(100\,\mathrm{Bq}\)
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\(0\,\mathrm{Bq}\)
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\(200\,\mathrm{Bq}\)
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\(400\,\mathrm{Bq}\)
Question 13
How can gamma radiation sterilise medical equipment?
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It damages microbes so they cannot reproduce
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It traces fluid flow through the equipment
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It measures the thickness of the equipment
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It makes the equipment emit visible light
Question 14
Why can a radioisotope act as a tracer?
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Its emitted radiation can be detected as it moves
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It changes the chemical properties of the fluid
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It colours the fluid along its path
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It blocks radiation outside the body
Question 15
Which radiation is most dangerous when inhaled?
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Alpha because it ionises strongly over a short range
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Gamma because it is absorbed in a short range
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Beta because it produces no ionisation
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Alpha because it passes straight out of the body
Question 16
Which is a natural source of background radiation?
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Cosmic rays and radioactive rocks
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Medical X-ray machines
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Current in domestic wiring
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Visible light from the Sun
Question 17
Which process splits a heavy nucleus into two smaller ones releasing energy?
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Fission
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Fusion
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Alpha decay
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Ionisation
Question 18
Why does nuclear fusion release energy in stars?
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Light nuclei join and some mass becomes energy
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Heavy nuclei split and gain extra mass
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Electrons join to form an alpha particle
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Neutrons turn directly into sound energy
Question 19
Why do isotopes have the same chemical behaviour?
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They have the same number of electrons
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They have the same mass number
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They emit the same radiation
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They contain the same number of neutrons
Question 20
How can one nuclear fission cause a chain reaction?
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Released neutrons cause further fissions
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Released electrons cause nuclear fusion
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Gamma rays turn directly into uranium
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The split nuclei rejoin immediately
Question 21
What did most alpha particles passing through foil show?
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Most of an atom is empty space
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Positive charge is spread evenly through the atom
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Electrons are concentrated inside the nucleus
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The nucleus fills most of the atom's volume
Question 22
What happens when alpha particles strike thin gold foil?
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Most pass through; a few deflect strongly
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Most rebound; a few pass through
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Similar numbers scatter at every angle
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Most stop inside the foil
Question 23
Which detection method records radiation counts per second?
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Geiger-Muller tube
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Voltmeter
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Spectrometer
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Barometer
Question 24
How can ionising radiation damage cells?
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Ionise molecules and break chemical bonds
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Warm molecules without changing their electrons
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Add neutrons to the nuclei of every cell
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Increase the mass of cell membranes
Question 25
Why is lead used to shield gamma radiation?
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Its high density absorbs gamma photons effectively
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Its magnetic field deflects gamma photons
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Its electric charge repels gamma photons
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Its low density lets gamma photons spread out
Question 26
What does an atom's mass number represent?
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Total protons and neutrons
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Total protons and electrons
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Neutrons minus protons
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Number of occupied electron shells
Question 27
What happens to an isotope's half-life if the sample size doubles?
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It stays the same
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It doubles
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It halves
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It becomes unpredictable
Question 28
A source has count rate \(800\,\mathrm{Bq}\) and half-life \(2\,\mathrm{h}\). What is its count rate after \(4\,\mathrm{h}\)?
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\(200\,\mathrm{Bq}\)
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\(400\,\mathrm{Bq}\)
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\(600\,\mathrm{Bq}\)
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\(100\,\mathrm{Bq}\)
Question 29
Why is radioactive decay described as random?
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An individual nucleus's decay time cannot be predicted
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Each nucleus decays at the same fixed age
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The sample's half-life changes after every decay
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The activity follows a repeating cycle
Question 30
Which material is suitable for absorbing beta radiation?
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A thin sheet of aluminium
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A sheet of paper
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A thick block of lead
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A transparent glass lens