Radioactivity (Cambridge O Level Physics)

Exam Questions

3 hours42 questions
1
Sme Calculator
1 mark

Radioactive materials are usually stored in containers lined with metal. This is done to reduce the amount of radiation being emitted, to protect people nearby.

What type of metal is used for this purpose?

  • Lead

  • Aluminium

  • Steel

  • Copper

Did this page help you?

2
Sme Calculator
1 mark

A student has three radioactive sources X, Y and Z. They devised the following experiment to determine what type of radiation each source is emitting. 

q2-easy-mcq-5-2-radioactivity-cie-igcse-physics

The student found that the radiation from X was stopped by a sheet of paper, Y was partially stopped by a few cm of lead and Z was stopped by a few mm of aluminium.

Which of the following correctly identifies each type of radiation

 

X

Y

Z

A

α-particle

β-particle

γ-ray

B

α-particle

γ-ray

β-particle

C

γ-ray

β-particle

α-particle

D

β-particle

γ-ray

α-particle

    Did this page help you?

    3
    Sme Calculator
    1 mark

    Which statement is not a method used to minimise the risk caused by working with radioactive sources.

    • Store the sources in lead-lined boxes.

    • Minimise the amount of time spent handling the sources.

    • Keep the source cold.

    • Keep the source as far away as possible, for example, using a pair of tongs.

    Did this page help you?

    4
    Sme Calculator
    1 mark

    Which statement about α-particles is correct?

    • α-particles consist of two protons and two electrons.

    • α-particles are the most penetrating type of radiation.

    • α-particles are a type of electromagnetic radiation.

    • α-particles are highly ionising.

    Did this page help you?

    5
    Sme Calculator
    1 mark

    There are three main types of radiation which may be emitted during radioactive decay: α-particles, β-particles and γ-rays.

    Which of the following statements about these types of emissions is true?

    • α-particles are the only type of radiation to have a charge.

    •  γ-rays are stopped by a sheet of paper.

    • β-particles have the greatest ionising effect.

    • γ-rays are the most penetrating

    Did this page help you?

    1
    Sme Calculator
    1 mark

    A student carried out an experiment to find the half-life of a radioactive substance. Their results are shown in the table below.

    Time(seconds) Count-rate from source(counts per second)
    0 300
    20 200
    40 150
    60 100
    80 75

    What is the half -life of this substance?

    • 20 seconds

    • 40 seconds

    • 60 seconds

    • 80 seconds

    Did this page help you?

    2
    Sme Calculator
    1 mark

    Strontium-90 is a radioactive substance with the nuclide symbol S presubscript 38 presuperscript 90 r .

    It decays by emitting radiation, as shown by the following equation.

    S presubscript 38 presuperscript 90 r space rightwards arrow Y presubscript 39 presuperscript 90 space plus space ?

    What is missing in this equation?

    • α-particle

    • Neutron

    • γ-ray

    • β-particle

    Did this page help you?

    3
    Sme Calculator
    1 mark

    A radioactive nucleus emits a β-particle.

    What happens to the proton number and the nucleon number of this nucleus?

     

    Proton number

    Nucleon number

    A

    increases by 1

    stays the same

    B

    stays the same

    decreases by one

    C

    decreases by 2

    decreases by 4

    D

    decreases by 1

    stays the same

      Did this page help you?

      4
      Sme Calculator
      1 mark

      The count rate from a radioactive isotope is recorded every hour. The count rate is corrected for background radiation. The table shows the readings.

      time / hours 0 1 2 3 4 5
      corrected count rate / counts/s 1200 990 816 673 555 458

      What estimate of the half-life of the isotope can be obtained from the readings in the table?

      • between 1 and 2 hours

      • between 2 and 3 hours

      • between 3 and 4 hours

      • between 4 and 5 hours

      Did this page help you?

      5
      Sme Calculator
      1 mark

      An nucleus of Uranium ( begin mathsize 24px style U presubscript 92 presuperscript 238 end style) is unstable and decays by emitting an α-particle. 

      Which equation correctly describes this process?

      • U presubscript 92 presuperscript 238 rightwards arrow alpha presubscript 2 presuperscript 4 plus T presubscript 90 presuperscript 234 h

      • U presubscript 92 presuperscript 238 rightwards arrow alpha presubscript 2 presuperscript 4 plus U presubscript 90 presuperscript 234

      • U presubscript 92 presuperscript 238 plus alpha presubscript 2 presuperscript 4 rightwards arrow T presubscript 90 presuperscript 234 h

      • U presubscript 92 presuperscript 238 rightwards arrow alpha presubscript 2 presuperscript 4 plus R presubscript 88 presuperscript 234 a

      Did this page help you?

      6
      Sme Calculator
      1 mark

      Radioactive isotopes emit three types of radiation.

      Which list gives the types of radiation in order of their ionising effect from greatest to least?

      • alpha-particles, beta-particles, gamma rays

      • alpha-particles, gamma rays, beta-particles

      • beta-particles, gamma rays, alpha-particles

      • gamma rays, beta-particles, alpha-particles 

      Did this page help you?

      7
      Sme Calculator
      1 mark

      Which statement about the half-life of a radioactive isotope is correct?

      • Half-life is half the time it takes for the mass of the isotope to decrease to zero.

      • Half-life is half the time it takes for the number of nuclei of the isotope to decrease to zero.

      • Half-life is the time taken for the nucleon number of the isotope to halve.

      • Half-life is the time taken for the number of nuclei of the isotope to halve.

      Did this page help you?

      8
      Sme Calculator
      1 mark

      Which statement about nuclear fusion is correct?

      • Nuclear fusion occurs at low temperatures.

      • Nuclear fusion occurs only between heavy nuclei. 

      • Nuclear fusion occurs in the formation of many stars. 

      • Nuclear fusion powers most electricity-generating stations. 

      Did this page help you?

      9
      Sme Calculator
      1 mark

      In one radioactive decay, radium-226 decays to radon-222 as shown. 

      q38-cie-ol-physics-paper-1-2021-mcq

      Which particles are also produced? 

      • both an alpha-particle and a beta-particle

      • an alpha-particle only 

      • a beta-particle only 

      • a neutron

      Did this page help you?

      10
      Sme Calculator
      1 mark

      The count rate from a radioactive source falls from 4000 counts per minute to 500 counts per minute in 72 minutes. 

      What is the half-life of the source?

      • 8 minutes

      • 9 minutes

      • 18 minutes

      • 24 minutes

      Did this page help you?

      1
      Sme Calculator
      1 mark

      Radioactive sources are often used in industry as part of manufacturing processes. The diagram below shows radiation being used to measure the thickness of a sheet of aluminium foil. The detector feeds back to the rollers to adjust the thickness.

      q1-hard-mcq-5-2-radioactivity-cie-igcse-physics

      What type of radiation would be the most suitable for this purpose?

      • α-particles

      • β-particles

      • γ-rays

      • All of the above.

      Did this page help you?

      2
      Sme Calculator
      1 mark

      The count rate of a radioactive material is measured using a detector. The reading on the detector is 88 counts per second. The background count rate is 40 counts per second.

      The half-life of the radioactive substance is 12 hours. What is the reading on the detector after 24 hours?

      • 22

      • 12

      • 44

      • 52

      Did this page help you?

      3
      Sme Calculator
      1 mark

      A radioactive substance has a half-life of 4 days. 

      It is currently emitting 8000 β-particles per minute.

      How many β-particles will it emit per minute after 12 days?

      • 4000

      • 2000

      • 1000

      • 667

      Did this page help you?

      4
      Sme Calculator
      1 mark

      Beta and gamma radiation are passed through two charged metal plates as shown in the diagram below.

      q4-hard-mcq-5-2-radioactivity-cie-igcse-physics

      Which direction, if any, would the β-particles and γ-rays be deflected?

       

      β-particles

      γ-rays

      A

      into the page

      continue straight

      B

      towards the negative plate

      out of the page

      C

      continue straight

      towards the negative plate

      D

      towards the positive plate

      continue straight

        Did this page help you?