isotopes

• What do isotopes of an element have in common?

  Same number of protons
• What distinguishes isotopes of an element?

  Different numbers of neutrons
• What is the atomic number of an element?

  Number of protons in an atom
• How is the mass number of an atom calculated?

  Protons plus neutrons in the nucleus
• What is the mass number of the oxygen atom represented as ¹⁶₈O?

  16
• How many protons does an oxygen atom have?

  8 protons
• How many neutrons are in the oxygen atom ¹⁶₈O?

  8 neutrons
• What are isotopes of an element?

  Atoms with the same protons but different neutrons
• How many stable isotopes do most elements have?

  Usually one or two stable ones
• What happens to unstable isotopes?

  They decay into other elements
• What is the process called when unstable isotopes decay?

  Radioactive decay
• What types of radiation do radioactive substances emit?

  Alpha, beta, and gamma radiation
• What can radioactive decay release besides radiation?

  Neutrons
• What is ionising radiation?

  Radiation that knocks electrons off atoms
• What does ionising power refer to?

  How easily radiation can knock off electrons
• What are the key characteristics of isotopes?

  • Same number of protons
  • Different number of neutrons
  • Different mass numbers
  • Can be stable or unstable
• What are the types of radiation emitted by radioactive substances?

  • Alpha radiation
  • Beta radiation
  • Gamma radiation
• What are the effects of ionising radiation?

  • Knocks electrons off atoms
  • Creates positive ions
  • Can cause damage to living tissue