2. Orbital Notation and Electron Configuration October 20th

3. Distance From The Nucleus  Called the Principle Quantum Number (n)  Describes the principle energy level  n = 1, 2, 3  Called the Principle Quantum Number (n)  Describes the principle energy level  n = 1, 2, 3

4. Shape of the Orbital  Described by Orbital quantum number (l)  Tells you the shape of the orbital the electron is in  Is it an s, p, d, or f orbital?  Described by Orbital quantum number (l)  Tells you the shape of the orbital the electron is in  Is it an s, p, d, or f orbital?

5. Position in 3D Space  Described by Magnetic Quantum Number (m)  Indicated the position of the orbital around the 3 axes (x, y, z)  Described by Magnetic Quantum Number (m)  Indicated the position of the orbital around the 3 axes (x, y, z)

6. Electron’s Spin  The direction of the electron’s spin is described by the spin quantum number  Electrons can be either up or down  When electrons are part of a pair, they must spin in opposite directions  The direction of the electron’s spin is described by the spin quantum number  Electrons can be either up or down  When electrons are part of a pair, they must spin in opposite directions

7. Pauli Exclusion Principle  No two electrons in the same atom can have the same four quantum numbers (the same description)  No two electrons can have the same address  Electrons are repulsed by each other, so they cannot live together… Hence makes sense they have opposite spins!  No two electrons in the same atom can have the same four quantum numbers (the same description)  No two electrons can have the same address  Electrons are repulsed by each other, so they cannot live together… Hence makes sense they have opposite spins!

8. Review Of Energy Levels  n = 1  s orbital (2 electrons)  n = 2  s orbital (2 electrons)  p orbital (6 electrons)  n = 3  s orbital (2 electrons)  p orbital (6 electrons)  d orbital (10 electrons)  n = 4  s orbital (2 electrons)  p orbital (6 electrons)  d orbital (10 electrons)  f orbital (14 electrons)  n = 1  s orbital (2 electrons)  n = 2  s orbital (2 electrons)  p orbital (6 electrons)  n = 3  s orbital (2 electrons)  p orbital (6 electrons)  d orbital (10 electrons)  n = 4  s orbital (2 electrons)  p orbital (6 electrons)  d orbital (10 electrons)  f orbital (14 electrons)

9. 3 Rules for Electron Configuration 1) Aufbau Principle - electrons occupy the orbitals of lowest energy first 2) Pauli Exclusion Principle - no two electrons can have the same address(same 4 quantum #s) 3) Hund’s Rule - Electrons try to occupy different orbitals before pairing up 1) Aufbau Principle - electrons occupy the orbitals of lowest energy first 2) Pauli Exclusion Principle - no two electrons can have the same address(same 4 quantum #s) 3) Hund’s Rule - Electrons try to occupy different orbitals before pairing up

11. Orbital Notation order in which electrons are filled

12. The Order in which orbitals fill…

13. Orbital Notation

14. Arrangement of Electrons in Atoms  Each orbital can be assigned no more than 2 electrons!  Each orbital can hold a pair of electrons per orientation  s1 orientation(pair) 2 electrons  p3 orientations 6 electrons  d5 orientations 10 electrons  f7 orientations 14 electrons  Each orbital can be assigned no more than 2 electrons!  Each orbital can hold a pair of electrons per orientation  s1 orientation(pair) 2 electrons  p3 orientations 6 electrons  d5 orientations 10 electrons  f7 orientations 14 electrons

15. Orbital Diagram _____ 1s __________ _____ _____ 2s 2px 2py 2pz __________ _____ _____ _____ _____ _____ _____ _____ 3s 3px 3py 3pz 3d _____ _____ _____ _____ _____ _____ _____ _____ _____ 4s 4px 4py 4pz 4d _____ _____ _____ _____ _____ _____ _____ _____ _____ 5s 5px 5py 5pz 5d _____ 6s

16. How Orbitals Fill…. _____ 1s __________ _____ _____ 2s 2px 2py 2pz __________ _____ _____ 3s 3px 3py 3pz _____ 1s __________ _____ _____ 2s 2px 2py 2pz __________ _____ _____ 3s 3px 3py 3pz

17. Electron Configuration – Strontium _____ 1s __________ _____ _____ 2s 2px 2py 2pz __________ _____ _____ _____ _____ _____ _____ _____ 3s 3px 3py 3pz 3d _____ _____ _____ _____ _____ _____ _____ _____ _____ 4s 4px 4py 4pz 4d _____ _____ _____ _____ _____ _____ _____ _____ _____ 5s 5px 5py 5pz 5d _____ 6s

18. Valence electrons are electrons in the outermost energy level of an atom. _____ 1s __________ _____ _____ 2s 2px 2py 2pz __________ _____ _____ 3s 3px 3py 3pz Valence electrons Example: Sulfur

19. Practice on your own!  Draw the orbital diagram for Calcium  Draw the orbital diagram for Silicon  Draw the orbital diagram for Calcium  Draw the orbital diagram for Silicon

20. Electron Configuration 1 1 s Energy Level Subshell (s, p, d, f) no. of electrons for H, atomic number = 1

21. Electron Configuration  Fortunately! Its like orbital diagrams but without drawing the orbitals…  Fill electrons into lower energy levels first  Follow order of filling  Remember how many electrons each level can hold: s holds 2, p holds 6, d 10, f 14  Fortunately! Its like orbital diagrams but without drawing the orbitals…  Fill electrons into lower energy levels first  Follow order of filling  Remember how many electrons each level can hold: s holds 2, p holds 6, d 10, f 14

22. Examples  Helium: 1s 2  Boron : 1s 2 2s 2 2p 1  Magnesium: 1s 2 2s 2 2p 6 3s 2  Bromine: 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 5  Helium: 1s 2  Boron : 1s 2 2s 2 2p 1  Magnesium: 1s 2 2s 2 2p 6 3s 2  Bromine: 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 5

23. 1s 1 1s 2 2s 2 2p 6 3s 1 1s 2 2s 2 2p 6 3s 2 1s 2 2s 2 2p 6 3s 2 3p 5 1s 2 2s 2 2p 6 3s 2 3p 6 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 3 Practice on your own! Hydrogen Sodium Magnesium Chlorine Argon Arsenic

24.  Octet rule - all elements want to have a full set of valence electrons  Atoms will lose or gain electrons in trying to achieve a full octet  Octet rule - all elements want to have a full set of valence electrons  Atoms will lose or gain electrons in trying to achieve a full octet Octet Rule

25. Octet Rule states that atoms will gain or lose electrons to achieve a full outermost energy level. This is usually 8 electrons (s 2 p 6 ). Example: Oxygen _____ 1s __________ _____ _____ 2s 2px 2py 2pz O Octet Rule