C2

C2

1. History of the atom

   • John Dalton = Atoms Solid Spheres
     • 1904 JJ Thompson Plum pudding Model
       • 1911 Rutherford positive nucleus and negative electrons around it
         • Bohr = shells of electrons that orbit a nucleus

2. The atom

   • Protons (+), Nutrons, Electrons (-)
     • 2 electrons in first shell. 8 in any other shell

3. Reactions of group 1

   • group one elements will react with a particular reactant to = same type of product.
     • react with oxygen in moist air = metal oxide
       • Lithium, Sodium, Potassium all stored in oli to preven reaction with air
         • Rubidium, Ceasium sealed in glasss tube in special conditions (very reactive)
           • Group 1 elements
             • Melting and boiling points decrease as go down group 1
             • very reactive - easily loose their 1 outermost shell electron
   • Reactions with cold water = hydroxide and hydrogen gas
     • reaction with chlorine = salt

4. Group 7 elements

   • = Halogens