Radioactive Decay

• What is alpha radiation?

  2 protons, 2 neutrons
• What will happen to the structure of the unstable 'parent' nucleus if an a-particle is emitted?

  • Proton number (Z) decreases by 2
  • Nucleon number (A) decreases by 4
• What is B- radiation?

  Fast moving electron
• What condition does the unstable 'parent' nucleus have that requires it to emit B- radiation?

  Nuclei that have too many neutrons
• What occurs in the nucleus that creates the B- particle?

  • A neutron decays into a proton and an electron. The electron is emitted as the beta particle
• What other particle is always created in B- radiation process?

  Antineutrino
• What will happen to the structure of the unstable 'parent' nucleus if a B- particle is emitted?

  • Proton number (Z) increases by 1
  • Nucleon number (A) dos not change
• What is B+ radiation?

  Fast moving positron
• What condition does the unstable 'parent' nucleus have that requires it to emit B+ radiation?

  Nuclei that have too many protons
• What occurs in the nucleus that creates the B+ particle?

  • Proton decays into a neutron and a positron
  • The positron is emitted as the beta particle
• What other particle is always created in B+ radiation process?


  Nuetrino
• What will happen to the structure of the unstable 'parent' nucleus if a B+ particle is emitted?

  • Proton number (Z) decreases by 1
  • Nucleon number (A) does not change
• What condition does the unstable 'parent' nucleus have that could mean electron capture might occur?

  Nuclei that have too many protons
• What occurs in the atom in the process of electron capture?

  • An electron in the inner energy shell is 'captured' by the nucleus
  • Proton changes into a neutron
• What other particle is always created in electron capture process?


  Neutrino
• What will happen once a vacancy in the inner electron shell is formed?

  Inner-shell vacancy is filled by an outer-shell electron, as a result an x-ray photon is emitted by the atom as the electron falls to a lower energy level
• Gamma radiation:

  • No change occurs in the number of protons or neutrons in the nucleus when it emits a y photon
  • A y photon is emitted if a nucleus has excess energy after it has emitted an a-particle or a B-particle