9-1 Topic 6 Radioactivity 1

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The diagram shows parts of a nuclear power station. Which part of the power station provides thermal (heat) energy from a chain reaction?


  • nuclear reactor
  • turbine
  • generator
  • condenser

Which part of the power station transfers kinetic energy into electrical energy?

  • nuclear reactor
  • boiler
  • turbine
  • generator

One isotope of the element potassium is potassium-40. A nucleus of potassium-40 is represented by. The number of neutrons in a nucleus of ptassium-40 is:


  • 19
  • 21
  • 40
  • 59

Which of these symbols is correct for the nucleus of a different isotope of potassium?


  • A
  • B
  • C
  • D

Use the graph to find the half-life of potassium-40.


  • 2500 million years
  • 1300 million years
  • 3000 million years
  • 650 million years

Some radioactive isotopes emit positrons. Positrons are used to make gamma rays. When a positron annihilates an electron, two gamma rays are produced. Which diagram shows the directions of the two gamma rays produced?


  • A
  • B
  • C
  • D

Many different types of radioactive isotope are used for the diagnosis and treatment of medical conditions. Iodine-123 is used as a radioactive tracer to diagnose thyroid problems. This tracer must have a half-life of (complete the sentence):

  • a few days
  • a few hours
  • less than a second
  • several weeks

Cobalt-60 is a radioactive substance. A nucleus of cobalt-60 contains 27 protons and 33 neutrons. The number of electrons in a neutral atom of cobalt-60 is

  • 87
  • 60
  • 33
  • 27

Gamma radiation from cobalt-60 can be used to destroy tumours. The diagram shows how gamma radiation is used to destroy a brain tumour. Gamma radiation is used because


  • gamma can penetrate further than alpha or beta
  • gamma is more ionising than alpha or beta
  • gamma is always safer than alpha or beta
  • gamma has a shorter half-life than alpha or beta

The unit of activity of a radioactive isotope is the

  • americium
  • becquerel
  • einstein
  • radium