9-1 Topic 6 Radioactivity

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Which one of these statements about alpha radiation is correct?

  • Alpha radiation has no charge.
  • Alpha radiation is very ionising.
  • Alpha radiation travels very far in air.
  • Alpha radiation is an electromagnetic wave.

When an atom emits an alpha particle its nucleus changes. Which describes the changes in the nucleus?

  • Proton number decreases by 2. Mass number decreases by 4.
  • Proton number increases by 2. Mass number decreases by 4.
  • Proton number decreases by 2. Mass number increases by 4.
  • Proton number increases by 2. Mass number increases by 4.

The three particles shown are:


  • A = proton, B = electron, C = neutron
  • A = neutron, B = electron, C = proton
  • A = neutron, B = neutron, C = electron
  • A = electron, B = neutron, C = proton

The size of the charge on an electron is:

  • a third of the charge on the proton
  • half the charge on the proton
  • the same as the charge on the proton
  • twice the charge on the proton

The atomic number of a neutral atom is always the same as the number of

  • electrons
  • electrons and neutrons
  • protons and neutrons
  • neutrons

The diagram shows the stability curve for nuclear isotopes. An isotope above the curve will undergo β− decay because it has:


  • too few protons
  • too many protons
  • too few neutrons
  • too many neutrons

Which statement is correct for β+ and β− particles?

  • a β+ is positively charged and a β− is negatively charged
  • the mass of a β+ is 1800 times the mass of a β−
  • the charge on a β+ is twice the charge on a β−
  • a β+ is a proton and a β− is an electron

Beryllium-9 has an atomic number of 4 and a mass number of 9. A nucleus of this isotope can be described using this symbol. The number of neutrons in this nucleus is:


  • 4
  • 5
  • 9
  • 13

The nucleus of a hydrogen atom can be represented by this symbol. The symbol shows that the nucleus consists of


  • 1 proton and 1 neutron
  • 1 proton only
  • 1 neutron only
  • 1 neutron and 1 electron.

Nuclear Fusion. High temperatures and pressures are needed in a nuclear fusion reactor. This is to overcome

  • the kinetic energy of nuclei
  • the electrostatic repulsion of protons
  • the magnetic repulsion of neutrons
  • nuclear fission