P4-Atomic structure

P4-Atomic structure

1. structure of the Atoms

   • proton
     • mass=1
     • charge=+1
   • neutron
     • charge=0
     • mass=1
   • electron
     • charge=1
     • mass=tiny

2. radioactivity

   • alpha
     • stopped by a only few cm in air skin and paper
     • charge 2+
     • mass 4
   • gamma
     • charge-0
     • weekly ironising
     • stopped by a few meters of thick lead and concreate
     • mass 0
   • beta
     • charge -1
     • fairly strongly ironising
     • mass 1/1832
     • stopped by AI foil
     • fast moving electron

3. history of an atom

   • Democritus
     • atoms are invisible
   • James Chadwick
     • discoved neutrons
   • JJ thompson
     • plum pudding model
       • solid ball off positive charge dotted with negative charge
   • niels bohr
     • electrons are in cells
   • john dalton
     • atoms are building blocks there are diffrent types