1. Dr. S. M. Condren Chapter 8 Electron Configuration and Periodicity

2. Dr. S. M. Condren Orbitals region of probability of finding an electron around the nucleus 5 types => s p d f g maximum of 2 electrons per orbital

3. Dr. S. M. Condren Pure Atomic Orbitals shape # of orbitals / energy level s spherical 1 p dumbbell 3 d complex 5 f very complex 7 gextremely complex 9

4. Dr. S. M. Condren Pauli Exclusion Principle

5. Dr. S. M. Condren Electronic Configurations The shorthand representation of the occupancy of the energy levels (shells and subshells) of an atom by electrons.

6. Dr. S. M. Condren Electronic Configuration shells=>energy levels subshells=>orbitals

7. Dr. S. M. Condren

8. Regions by Electron Type

9. Dr. S. M. Condren Electron Filling Order Diagram 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f 5s 5p 5d 5f 6s 6p 6d 7s 7p Start here

10. Dr. S. M. Condren Electronic Configuration H atom 1 electron 1s 1

11. Dr. S. M. Condren Electronic Configuration He atom 2 electrons 1s 2

12. Dr. S. M. Condren Electronic Configuration Li atom 3 electrons 1s 2, 2s 1

13. Dr. S. M. Condren Electronic Configuration Cl atom 17 electrons 1s 2, 2s 2, 2p 6, 3s 2, 3p 5

14. Dr. S. M. Condren Electronic Configuration As atom 33 electons 1s 2, 2s 2, 2p 6, 3s 2, 3p 6, 4s 2, 3d 10, 4p 3 or [Ar] 4s 2, 3d 10, 4p 3

15. Dr. S. M. Condren Mn: [Ar]4s 2 3d ? How many d electrons does Mn have? 4, 5, 6

16. Dr. S. M. Condren

17. Electronic Configuration negative ions add electron(s), 1 electron for each negative charge

18. Dr. S. M. Condren Electronic Configuration S -2 ion (16 + 2)electrons 1s 2, 2s 2, 2p 6, 3s 2, 3p 6

19. Dr. S. M. Condren Electronic Configuration positive ions remove electron(s), 1 electron for each positive charge

20. Dr. S. M. Condren Electronic Configuration Mg +2 ion (12-2)electrons 1s 2, 2s 2, 2p 6

21. Dr. S. M. Condren How many valence electrons are in Cl, [Ne]3s 2 3p 5 ? 2, 5, 7

22. Dr. S. M. Condren For Cl to achieve a noble gas configuration, it is more likely that electrons would be added electrons would be removed

23. Dr. S. M. Condren

24. Trends in the Periodic Table atomic radius ionic radius ionization energy electron affinity

25. Dr. S. M. Condren Atomic Radius decrease left to right across a period as nuclear charge increases, number of electrons increase; however, the nucleus acts as a unit charge while the electrons act independently, pulling electrons towards the nucleus, decreasing size

26. Dr. S. M. Condren Atomic Radius increase top to bottom down a group each additional electron “shell” shields the outer electrons from the nuclear charge Z eff = Z – S where Z eff => effective nuclear charge Z => nuclear charge, atomic number S => shielding constant

27. Dr. S. M. Condren Atomic Radius increases from upper right corner to the lower left corner

28. Dr. S. M. Condren Atomic Radius vs. Atomic Number

29. Dr. S. M. Condren Atomic Radius

30. Dr. S. M. Condren Ionic Radius same trends as for atomic radius positive ions smaller than atom negative ions larger than atom

31. Dr. S. M. Condren Ionic Radius Isoelectronic Series series of negative ions, noble gas atom, and positive ions with the same electronic confiuration size decreases as “positive charge” of the nucleus increases

32. Dr. S. M. Condren Ge is a semiconductor. If half of the Ge atoms of a sample of Ge are replaced with Ga atoms, with what element should the other half of the Ga atoms be replaced in order for this new compound to be isoelectronic with Ge? Sn, As, Se

33. Dr. S. M. Condren Ionization Energy energy necessary to remove an electron to form a positive ion low value for metals, electrons easily removed high value for non-metals, electrons difficult to remove increases from lower left corner of periodic table to the upper right corner

34. Dr. S. M. Condren Ionization Energies first ionization energy energy to remove first electron from an atom second ionization energy energy to remove second electron from a +1 ion etc.

35. Dr. S. M. Condren Ionization Energy vs. Atomic Number

36. Dr. S. M. Condren Electron Affinity energy released when an electron is added to an atom same trends as ionization energy, increases from lower left corner to the upper right corner metals have low “EA” nonmetals have high “EA”

37. Dr. S. M. Condren Magnetism Result of the spin of electrons diamagnetism - no unpaired electrons paramagnetism - one or more unpaired electrons ferromagentism - case of paramagnetism where the substance retains its magnetism

38. Dr. S. M. Condren Magnetism Paramagnetism Ferromagnetism Without applied field With applied field