Atomic Structure

Atomic Structure

1. Isotopes

   • mass number-top
   • atomic number- bottom
   • different number of neutrons

2. energy shells

   • first shell
     • 2 electrons
   • +second shell
     • 8 electrons

3. electronic structure

   • dot and cross diagrams
     • this helps see what group the elements in

4. Atomic theories

   • Daltons Theory
     • 1800s
     • "all matter made from atoms"
     • "atoms cant be broken into anything simpler"
     • all atoms of an element are identical to eachother
     • atoms rearranged in a chemical reaction
     • compounds formed when +2 different atoms join
   • JJ Thompson
     • discovered the electron
       • 1897
     • "an atom contains smaller pieces"
   • Rutherford
     • discovered the nucleus
       • 1911
   • Bohr
     • "electrons orbit nucleus"
     • experiements