nuclear radiation and decay

• Stable nuclei


  Nuclei that contain a certain amount of neutrons compared to protons
• Unstable nuclei


  Nuclei with too few or too many neutrons
• Radioactive decay


  A random process in which an unstable nucleus will emit one or more types of nuclear radiation to become more stable

  
• Nuclear radiation


  Radiation emitted from an unstable nucleus during radioactive decay

  
• Types of nuclear radiation

  Alpha particle, beta particle, gamma ray, neutron
• Alpha particle (α)


  Consists of two neutrons and two protons and is identical to a helium nucleus

  
• Beta-minus particle (β-)


  A high speed electronejected from the nucleus

  
• Beta-plus particle (β+)


  A high speed positronejected from the nucleus

  
• Gamma ray (γ)


  Electromagnetic radiation from the nucleus

  
• Change to the nucleus due to alpha decay

  The nucleus loses two protons and two neutrons

  
• Effect of alpha decay on atomic and mass numbers

  The mass number decreases by four and the atomic number decreases by two

  
• Change to the nucleus due to beta-minus decay

  A neutron turns into a proton

  
• Effect of beta-minus decay on atomic and mass numbers

  The atomic number increases by one and the mass number remains the same

  
• Change to the nucleus due to beta-plus decay

  A proton turns into a neutron

  
• Effect of beta-plus decay on atomic and mass numbers

  The atomic number decreases by one and the mass number remains the same

  
• Change to the nucleus due to gamma decay


  There is no change to the particles in the nucleus

  
• Effect of gamma decay on atomic and mass numbers


  There is no change to the atomic or mass numbers