Isotopes

• Isotopes


  Atoms of the same element that have the same number of protons but different numbers of neutrons
• Isotopes of an element look pretty similar, but they have different numbers of neutrons
• Atomic number


  The number of protons in an atom's nucleus
• Mass number


  The number of protons + the number of neutrons in an atom's nucleus
• Oxygen isotope


  • Oxygen-16
• Oxygen has an atomic number of 8, meaning all oxygen atoms have 8 protons</b>
• The oxygen-16 atom has a mass number of 16, so it must have 8 neutrons
• Alpha radiation


  • Emitted by radioactive substances
  • Highly ionising
• Beta radiation


  • Emitted by radioactive substances
  • Moderately ionising
• Gamma radiation


  • Emitted by radioactive substances
  • Weakly ionising
• Radioactive substances can also release neutrons when they decay
• Ionising radiation


  Radiation that knocks electrons off atoms, creating positive ions
• The ionising power of a radiation source is how easily it can knock electrons off atoms