Radioactive emissions

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Question 21
Medium

This question is about radioactive isotopes and nuclear processes.

a.

Radium-226 can be used to generate heat in small-scale thermo-electric devices:

  • The Radium-226 undergoes radioactive decay.
  • This causes the temperature of the radium and its surroundings to increase.
  • Heat energy is then transferred.

Complete the sentences using the words below. You can use each word once, more than once, or not at all.

chemicalelastic potentialelectrostatic \text{chemical} \qquad \text{elastic potential} \qquad \text{electrostatic} chemicalelastic potentialelectrostatic gravitational potentialnuclearthermal \text{gravitational potential} \qquad \text{nuclear} \qquad \text{thermal} gravitational potentialnuclearthermal
  • The ............................................................ energy store of the radium decreases.
  • The ............................................................ energy store of the radium increases.
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b.

State why a Radium-226 nucleus undergoes radioactive decay.

[1]
c.

A Radium-226 nucleus emits an alpha particle (which consists of 2 protons and 2 neutrons).

88226Ra \vphantom{}^{226}_{88}\text{Ra} 88226​Ra

Determine the value of the mass number and the number of protons of the nucleus after the Radium-226 emits this alpha particle.

  • Mass number: ............................................................
  • Number of protons: ............................................................
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d.

Use the graph below, which shows how the activity of a sample of Cesium-137 changes with time, to find its half-life.

Graph plotting Activity in MBq against Time in years. The vertical axis begins at 0 and goes up to 90 MBq, with major grid lines every 10 MBq and minor grid divisions every 2 MBq. The horizontal axis starts at 0 and goes up to 150 years, with major grid lines every 30 years and minor grid divisions every 5 years. A smooth exponential decay curve starts at (0, 80), passes through (30, 40), (60, 20), (90, 10), and (120, 5).

Show your working on how you obtained this value from the graph.

Half-life = ............................................................ years

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e.

Describe how a chain reaction occurs in the nuclear fission of Uranium-235.

[2]
f.

Nuclear fusion occurs in stars. Describe what is meant by nuclear fusion.

[1]

Radioactive emissions Questions

  1. GCSE
  2. /Physics
  3. /Radioactive emissions