Atomic Structure

• This is an atomic structure

  
• Protons and neutrons are found in the nucleus, electrons orbit the nucleus in shells (energy levels).

  
• Atoms have a radius of around 0.1nm

  = 1 x 10-10 m
• The nucleus has a radius around 1/10,000 that of an atom = 1 x 10-14 m
• To convert nm to m: x 10-9
• To convert m to nm: ÷ 10-9
• What is the Relative mass of a proton?


  1
• What is the relative charge of a proton?


  +1
• What is the relative mass of a neutron?


  1
• What is the relative charge of a neutron?


  0
• What is the relative mass of an electron?


  Almost 0
• What is the relative charge of an electron?


  -1
• Atomic number = number of protons (also the number of electrons (in a neutral atom)

  Mass number = no of protons + no of neutrons

  So: no of neutrons = mass number – atomic

  number
• Lithium has a

  Number of protons = 3

  Number of electrons = 3

  Number of neutrons = 7-3 = 4