atomic structure

• Atom


  A very small particle that makes up all matter
• Nucleus


  The central region of an atom
• Atoms have a radius around 1 * 10^-10 m
• The radius of the nucleus is less than 1/1000th the radius of the atom</b>
• Almost all the mass of an atom is concentrated in the nucleus
• The radius of the nucleus is less than 1,000th the radius of the atom</b>
• Protons


  Particles in the nucleus with a positive charge
• Neutrons


  Particles in the nucleus with no charge (neutral)
• Electrons


  Negatively charged particles surrounding the nucleus
• Energy levels


  Regions at different distances from the nucleus where electrons can be found
• The nucleus has an overall positive charge due to the protons
• Electron arrangement changes when radiation is absorbed or emitted

  1. Electron moves from lower to higher energy level when radiation is absorbed

  2. Electron returns to lower energy level when radiation is emitted
• Energy levels


  Regions at different distances from the nucleus where electrons can be found
• Energy levels further from the nucleus are at higher energy
• Electron arrangement changes when radiation is absorbed or emitted

  1. Electron moves from lower to higher energy level when radiation is absorbed

  2. Electron returns to lower energy level when radiation is emitted