1. ELECTRONS IN ATOMS

2. Address of electrons in atoms

3. ELECTRONS IN ORBIT ABOUT THE NUCLEUS

4. e - density (1s orbital) falls off rapidly as distance from nucleus increases Where 90% of the e - density is found for the 1s orbital ELECTRON DENSITY OF 1s ORBITAL

5.  = fn(n, l, m l, m s ) ______________________________ l for a given value of n, l = 0, 1, 2, 3, … n-1 n = 1, l = 0 n = 2, l = 0 or 1 n = 3, l = 0, 1, or 2 Shape of the “volume” of space that the e - occupies l = 0 s orbital l = 1 p orbital l = 2 d orbital l = 3 f orbital Schrödinger Wave Equation

6. l = 0 (s orbitals) l = 1 (p orbitals)

7. l = 2 (d orbitals)

8. m l = -1m l = 0m l = 1 m l = -2m l = -1m l = 0m l = 1m l = 2

9. Energy of orbitals in a single electron atom Energy depends only on principal quantum number n E n = -R H ( ) 1 n2n2 n=1 n=2 n=3

10. Energy of orbitals in a many-electron atom Energy depends on n and l n=1 l = 0 n=2 l = 0 n=2 l = 1 n=3 l = 0 n=3 l = 1 n=3 l = 2

11. Fill lowest energy orbitals first (Aufbau principle) He 2 electrons He 1s 2

12. Fill lowest energy orbitals first (Aufbau principle) Li 3 electrons Li 1s 2 2s 1

13. Fill lowest energy orbitals first (Aufbau principle) Be 1s 2 2s 2 Be 4 electrons

14. Fill lowest energy orbitals first (Aufbau principle) B 5 electrons B 1s 2 2s 2 2p 1

15. Fill lowest energy orbitals first (Aufbau principle) C 1s 2 2s 2 2p 2 C 6 electrons ?

16. C 1s 2 2s 2 2p 2 Hund’s rule: The most stable arrangement of electrons in subshells is the one with the greatest number of parallel spins.

17. N 7 electrons N 1s 2 2s 2 2p 3 ? Hund’s rule: The most stable arrangement of electrons in subshells is the one with the greatest number of parallel spins.

18. N 7 electrons N 1s 2 2s 2 2p 3 Hund’s rule: The most stable arrangement of electrons in subshells is the one with the greatest number of parallel spins.

19. O 8 electrons O 1s 2 2s 2 2p 4 Hund’s rule: The most stable arrangement of electrons in subshells is the one with the greatest number of parallel spins.

20. F 9 electrons F 1s 2 2s 2 2p 5 Hund’s rule: The most stable arrangement of electrons in subshells is the one with the greatest number of parallel spins.

21. Ne 10 electrons Ne 1s 2 2s 2 2p 6 Hund’s rule: The most stablearrangement of electrons in subshells is the one with the greatest number of parallel spins.

22. Order of orbitals (filling) in multi-electron atom 1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p < 5s < 4d < 5p < 6s

23. Outermost subshell being filled with electrons

24. Electrons determine all of the chemical properties and some of the physical properties of elements.