Atomic structure, isotopes and electron shells

• Ores Science
• Biology x2
• Atomic Structure
• Atomic structure, Isotopes & electron shows
• Nucleus


  Contains:

  • protons (+)
  • neutrons
  • relative mass Of 1
• Electrons


  Orbit in shells
• Electrons are 2000x smaller
• Electron charge


  1. charge
• Nuclear symbol


  Li elemental symbol
• Atomic number


  Protons determine which element it is
• Mass number


  7 (protons + neutrons)
• Protons and neutrons make up the nucleus
• Electrons are the same for atoms of the same element
• Isotopes


  Atoms with the same number of PROTONS, but different number of neutrons (mass no.)
• Some of an element's isotopes are stable, some are radioactive
• Radioactive decay can produce alpha, beta, gamma radiation
• Radioactive decay


  Emission of radiation
• Electrons


  Arranged in shells, increasing in energy level as shells go outwards
• Electron excitation


  Electrons can gain enough energy to move to a higher energy shell
• Electron de-excitation


  Electrons will soon fall back down to their original shell and emit electromagnetic radiation
• Ionisation


  Electron could absorb so much energy it is able to completely leave the atom, leaving the atom with more protons than electrons and a positive charge
• Ionising radiation


  Able to knock electrons off atoms