3 Background Information Groups = vertical columnsPeriods = horizontal rows
4 Describing Orbitals e-s exist in shells surrounding the nucleus Lewis dot structures – show valence shell of e-s onlycan be used to show bonding
5 Describing Orbitals – cont’d Bohr Models – show basically same info but includes also the other levels used to figure out valence e-further knowledge has shown that e-s actually move in a cloud, taking up more than just ringsmodel to the right is about 70 years out of date!!
6 Quantum Numbers Quantum #s – describe the “clouds” of e-s First E Level = “s”up to 2 e-sSecond E Level = “p”up to 6 e-sThird E Level = “d”up to 10 e-s…that’s as high as we’re going to go
7 Quantum Numbers – cont’d 1s(up to 2)2s(up to 2)Levels fill from lowest (s) to highest (d-for our purposes…)2p(up to 6)3s(up to 2)3p(up to 6)4s(up to 2)3d(up to 10)4p(up to 6)***the 4th level “s” fills before the 3rd “d” level!!!!!
8 Quantum #s Examples Hydrogen – # of e-s = [recall: atoms are neutral] = 1e-s determine shellswill only fill part of the first “s” orbitalwe note this as “ 1s1 ” meaning 1st s orbital w/ 1 e-
9 Quantum #s Examples Phosphorous – # of e-s = [recall: atoms are neutral] = 15e-s determine shells15 e-s; fill from bottom upnotation:1s22s22p63s23p3
10 Quantum #s Examples Manganese – # of e-s = [recall: atoms are neutral] = 25e-s determine shells25 e-s; fill from bottom upnotation:1s22s22p63s23p64s23d5
11 Quantum #s & Periodic Table Period Indicates Quantum Numbers!!! Just count across the periods…