Periodic Table

Periodic Table

1. Electron Shells

   • Electron Configuration is 2,8,8,2
   • Nucleus contains the protons and the neutrons
   • Protons have a relative mass of 1 and a charge of +1
   • Neutrons have a relative mass of 1 and a neutral charge
   • Electrons have a very small mass and a -1 charge

2. Keys

   • Atomic number is the number of protons in the atom
     • Also the number of electrons in an atom
   • Mass number is the number of protons and neutrons

3. Groups and Periods

   • The vertical columns are called groups
   • Horizontal rows are called periods
   • Group 7 is known as halogens
   • Group 8 are known as noble gases