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• Isotope


  
  

  • An element that has one or more variations with a different number of neutrons and therefore atomic mass.
  • The atomic number always stays the same.
• Isotope notation


  • The atomic mass is written after the element name to indicate which isotope it is referring to. For example, in Carbon-13, "13" refers to the atomic mass.
  • When writing element symbols in isotopes, the atomic number is written as a subscript in the bottom left-hand corner of the symbol.
• Why do isotopes of the same element have the same chemical properties but different physical properties?


  Isotopes of the same element have the same chemical properties but different physical properties because they have the same number of protons and electrons which affects their chemical properties but different numbers of neutrons which affects physical properties like mass.
• Alpha Radiation

  • Contains two protons and two neutrons (Helium)
  • Has no electrons, so its overall charge is +2 (has high energy)
  • Can't penetrate far: can be stopped by a piece of paper
  • Strong ionising
  • Emission: particles are heavy and relatively slow
• Beta radiation

  • Contains only electrons
  • Has no protons: its overall charge is -2
  • Can penetrate moderately far: can be stopped by Aluminium
  • Moderately ionising
  • Due to having a small mass, it can be released with high speed and energy
• Gamma Radiation

  • Type of electromagnetic wave that can move at the speed of light
  • Has no mass or charge
  • Weakly ionising
  • Strong penetration: can be stopped by thick concrete
• Alpha decay Formula


  Formula:

  
• Beta decay formula


  Formula:

  
• Gamma decay formula


  Formula:

  
• Radioisotopes


  A radioactive isotope, or a radioisotope, is a chemical element with an unstable combination of neutrons and protons, or excess energy in its nucleus, that releases radiation as it breaks down and becomes more stable. They may occur naturally, or be made in laboratories by artificially altering the atom.
• Stable Isotopes


  Isotopes that don't emit radiation and don't decay into other elements.
• How are radioisotopes dangerous?


  Radioisotopes can be dangerous as they emit radiation and excess exposure to vast amounts of radiation can be harmful to the human body. However, if the use of radioisotopes is monitored and controlled, they are a valuable tool in medicine and can help treat diseases and cancers.
• Which two types of radiation are from particles?

  Alpha and Beta
• Which type of radiation is from electromagnetic waves?


  Gamma
• What determines the stability of an isotope?


  The stability of an isotope depends on its neutron-to-proton ratio. The higher the neutron-to-proton ratio (the more neutrons there are compared to protons), the more unstable and therefore radioactive an isotope is.
• Ionising Radiation

  Ionising radiation is a type of radiation that carries enough energy to remove electrons from atoms, creating charged particles called ions.
• Natural Radiation


  A form of radioactivity that originates from naturally occurring radioactive substances as opposed to being induced by human activities. It is a spontaneous process that occurs in certain elements, such as uranium, radon, and thorium.
• All radioactive substances contain one or more radioisotopes.
• Examples of stable isotopes


  • Carbon - 12
  • Carbon - 13
  • Nitrogen - 15
  • Potassium - 39
  • Chlorine - 37
• Nuclear Radiation


  Radiation that comes from the nucleus of the atom
• Examples of Alpha Radiation


  • Americium - 241
  • Uranium - 238
  • Radium - 226
• Examples of Beta Radiation


  • Carbon - 14
  • Strontium - 90
• Examples of Gamma Radiation


  • Cobalt - 60
• Properties of the emissions from radioactive sources


  • Can be detected with a Geiger counter
  • Turn photographic film black.
  • Cause phosphorescent materials to glow.
  • Can damage living cells
  • Can cause cancer in living things.
• Geiger counter


  Electronic instrument used for detecting and measuring ionising radiation
• Radioactivity in terms of alpha particles


  • Alpha radiation comes from radioisotopes that undergo alpha decay.
  • During alpha decay, the radioisotope changes into a different isotope.
  • The new isotope has two fewer protons and two fewer neutrons than the original isotope.
  • The atomic number decreases by two, and the mass number decreases by four
• Radioactivity in terms of beta particles


  • Beta radiation comes from radioisotopes that undergo Beta decay.
  • During beta decay, the radioisotope changes into a different isotope.
  • The new isotope has one more proton and one fewer neutrons than the original isotope. (We can view this as one neutron changing into a proton).
  • The atomic number increases by one, and the mass number is unchanged.
• Radioactivity in terms of gamma decay 


  • It does not involve a change in the element, unlike alpha and beta decay 
  • It's a simple decay from an excited state to a lower (ground) state.
  • In the process, some energy is released that is carried away by a photon