Atoms

Atoms

1. Parts:

   • Nucleus
     • protons
       • 1 amu
       • positive charge
     • neutrons
       • Protons+neutrons=atomic mass
       • 1 amu
       • no charge
   • Electron cloud
     • electrons
       • the number of electrons and protons MUST be the same in a neutral atom
       • negative charge

2. Isotopes

   • different number of neutrons
   • electrons and protons are still the same
   • 2H

3. Ions

   • negative/positive charge
   • different number of protons and neutrons
   • Na2-

4. Radioactivity

   • made up of particles
   • when atom releases radiation, it changes into different element
   • Alpha decay
     • unstable nucleus
       • two fewer protons and two fewer neutrons=
         • =alpha particle
   • Beta decay
     • unstable nucleus
       • one neutron changes into a proton
         • one fewer electron=
           • =beta particle
   • Gamma rays
     • no change in element