1. ATOMIC STRUCTURE Electron Configuration Building the Atom

2. ATOMIC STRUCTURE Remember… Atomic Number (Z) : the number of protons in the nucleus of the atom. Mass Number (A) : the number of protons and neutrons in the nucleus of the atom. Neutron Number (N) : A - Z = N

3. ATOMIC STRUCTURE LOCATION OF ELECTRONS IN THE ATOM: Electron CloudElectron Cloud Energy LevelsEnergy Levels SublevelsSublevels OrbitalsOrbitals

4. ATOMIC STRUCTURE LOCATION OF ELECTRONS IN THE ATOM: Sublevels have (degenerate states) thatSublevels have (degenerate states) that we call orbitals. we call orbitals. These sublevels are named s, p, d, f, g, etc. The energy level determines the number of sublevels...

5. ATOMIC STRUCTURE LOCATION OF ELECTRONS IN THE ATOM: Sublevels: s- one orbital p- three orbitals d- five orbitals f- seven orbitals Etc...

6. ATOMIC STRUCTURE LOCATION OF ELECTRONS IN THE ATOM: It turns out, in each orbital, there can be a maximum of two electrons. So... s-2 electrons total p-6 electrons total d-10 electrons total f-14 electrons total

7. ATOMIC STRUCTURE Orbital diagrams and electron configurations Orbital diagrams help show how the electrons are distributed within the sublevels. 1s NOTICE THAT WHEN ELECTRONS PAIR THEY HAVE OPPOSITE SPINS.

8. ATOMIC STRUCTURE PAULI EXCLUSION PRINCIPLE... No two electrons can have the same quantum numbers or no more than two electrons can be found in any given orbital.

9. ATOMIC STRUCTURE HUND’S RULE: the most stable arrangement of electrons is that with the maximum number of unpaired electrons, all with the same spin direction. In other words…electrons don’t pair until they have too!

10. ATOMIC STRUCTURE Orbital Diagrams 1s 2s 2p x 2p y 2p z 3s etc... What element is this????

11. ATOMIC STRUCTURE  Another way to write this is by using electron configuration notation 1s 2 2s 2 2p 6 3s 2

12. ATOMIC STRUCTURE ORDER OF CHOICE: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p... Why? Energy of some orbitals overlap higher orbitals. Page 97

13. ATOMIC STRUCTURE Let’s practice… Assignment: Electron Configuration Level One and Two Electron Configuration Wkst

14. ATOMIC STRUCTURE Orbital diagrams and electron configurations Orbital diagrams help show how the electrons are distributed within the sublevels. 1s NOTICE THAT WHEN ELECTRONS PAIR THEY HAVE OPPOSITE SPINS.

15. ATOMIC STRUCTURE Orbital Diagrams 1s 2s 2p x 2p y 2p z 3s etc... What element is this????

16. ATOMIC STRUCTURE  Another way to write this is by using electron configuration notation 1s 2 2s 2 2p 6 3s 2

17. ATOMIC STRUCTURE  Another way to write this is by using noble gas notation [Ne]3s 2 Since Ne has a configuration of 1s 2 2s 2 2p 6

18. ATOMIC STRUCTURE Let’s practice… Valence Electron Configuration

19. ATOMIC STRUCTURE Connections: Do you see any relationship between the electron configuration and where the element is located on the Periodic Table?

20. ATOMIC STRUCTURE You should be able to… Write the electron configuration Draw the orbital diagram Write the noble gas notation And predict the element

21. ATOMIC STRUCTURE Assignment: Electron Configuration Wkst 2