Types of radioactive decay and nuclear radiations

• What is the main focus of the study material?

  Nuclear radiation and types of radioactive decay
• What happens to unstable nuclei?

  They can decay by emitting alpha or beta particles and gamma radiation
• What are the types of radioactive decay mentioned?

  • Alpha decay
  • Beta minus decay
  • Beta plus decay (positron emission)
  • Gamma radiation
  • Neutron emission
• What is an alpha particle composed of?

  Two protons and two neutrons

  
• How is an alpha particle represented?

  As $^{4}_{2}\text{He}$ or $^{4}\alpha$
• What effect does alpha decay have on the mass and atomic number of a nucleus?

  Mass number decreases by four and atomic number decreases by two
• What occurs during beta minus decay?

  A neutron turns into a proton and emits a fast-moving electron
• How is a beta minus particle represented?

  As $^{0}_{-1}\text{e}$ or $^{0}_{-1}\beta$
• What is the effect of beta minus decay on the atomic and mass numbers?

  Atomic number increases by one and mass number remains the same
• What is a positron?

  A positron is the antimatter version of an electron with a +1 charge
• What happens during positron emission?

  A proton turns into a neutron and emits a fast-moving positron
• What is the effect of positron emission on the atomic and mass numbers?

  Atomic number decreases by one and mass number remains the same
• What is gamma radiation?

  It is a high-frequency electromagnetic wave emitted from a nucleus
• What happens to the nucleus after emitting an alpha or beta particle?

  The nucleus may still have excess energy and can emit gamma radiation
• What is the effect of gamma radiation on the atomic and mass numbers?

  There is no change in the number of particles in the nucleus
• What can occasionally happen during radioactive decay?

  A neutron can be emitted
• How can neutron emission occur naturally?

  Through the absorption of cosmic rays in the atmosphere
• What is one artificial method of neutron emission?

  Firing alpha particles at beryllium
• What happens to the mass and atomic numbers during neutron emission?

  Mass number decreases by one and atomic number remains the same
• What are the properties of different types of nuclear radiation?

  • Alpha:
  • Penetrating power: Skin/paper
  • Ionising power: High
  • Range in air: < 5 cm
  • Beta:
  • Penetrating power: 3 mm aluminum foil
  • Ionising power: Low
  • Range in air: ≈ 1 m
  • Gamma:
  • Penetrating power: Lead/concrete
  • Ionising power: Very low
  • Range in air: > 1 km

  
• How can all types of radioactive decay be detected?

  Using photographic film or a Geiger-Muller tube
• How does photographic film detect radiation?

  It is chemically changed by the radiation and can be developed
• How does a Geiger-Muller tube work?

  Radiation ionises the gas inside, and charged particles are counted
• What is the purpose of the study material?

  To provide information on nuclear radiation and radioactive decay