Electronic structure

• Electrons always occupy shells
• Which energy levels are filled up first?


  The lowest, close to the nucleus
• What is the structure for electronic configuration?


  2,8,8
• Which group have atoms with a full outer shell?

  Noble gases, Group 0
• If the outer shell is full, the atom is unreactive.
• In most atoms, the outer shell is not full and the atom wants to react to fill it.
• In most atoms, the outer shell is not full and the atom wants to react to fill it.
• How can you work out the electronic structures for the first 20 elements?


  Use the atomic number to work out the number of electrons, and then use the 2,8,8 rule to work out the rest.