radioactivity

radioactivity

1. structure of the atom

   • protons
     • charge:1
     • mass:+1
   • Neutrons
     • charge:none
     • mass:1
   • electrons
     • mass:1/1840
     • charge:-1

2. structure of the nucleus

   • X: shows us a symbol and tells us what the element is
   • A: known as the mass no. or the nucleon no. (p +n)
     • tells the no. of protons and neutrons
       • No. of Neutrons= mass no.- atomic no.
   • Z: known as the atomic no. or proton no.
     • tells us the no. of proton and what element it is

3. historical development of the atomic structure

   • alpha particle scattering experiment observation
     • most alpha particle went straight through the foil
       • atoms are mostly space
     • a few were deflected through large angles