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Chapter08 Atomic Structure and the Periodic Table. General Bibliography 1) Various wikipedia, as specified 2) Thornton-Rex, Modern Physics for Scientists & Eng, as indicated. Outline. 8.1 Atomic Structure and the Periodic Table 8.2 Total Angular Momentum. H-atom Energy Level Scheme. 4s.
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Chapter08Atomic Structure and the Periodic Table General Bibliography 1) Various wikipedia, as specified 2) Thornton-Rex, Modern Physics for Scientists & Eng, as indicated
Outline • 8.1 Atomic Structure and the Periodic Table • 8.2 Total Angular Momentum
H-atom Energy Level Scheme 4s 4p 4d 4f 3s 3p 3d 2s 2p 1s
orbitals get sucked down the most Crossings occur for the upper orbitals 4p 3d 4s 3p 3s 2p 2s 1s 1s sucked off bottom of page
http://chemistry.about.com/od/periodictables/Periodic_Tables.htm&docid=vGs4R7cWOxUJLM&imgurl=http://www.ithaca.edu/hs/chemistry/tablebig.jpg&w=600&h=327&ei=0wOqTqLOGYn20gHE-ZSIDw&zoom=1&iact=rc&dur=404&sig=111472812632995117326&page=2&tbnh=104&tbnw=191&start=16&ndsp=16&ved=1t:429,r:9,s:16&tx=111&ty=55http://chemistry.about.com/od/periodictables/Periodic_Tables.htm&docid=vGs4R7cWOxUJLM&imgurl=http://www.ithaca.edu/hs/chemistry/tablebig.jpg&w=600&h=327&ei=0wOqTqLOGYn20gHE-ZSIDw&zoom=1&iact=rc&dur=404&sig=111472812632995117326&page=2&tbnh=104&tbnw=191&start=16&ndsp=16&ved=1t:429,r:9,s:16&tx=111&ty=55
http://www.forevergeek.com/2010/10/there-is-a-periodic-table-for-that-15-periodic-tables-for-your-geekgasmic-pleasures/http://www.forevergeek.com/2010/10/there-is-a-periodic-table-for-that-15-periodic-tables-for-your-geekgasmic-pleasures/
http://www.gamepro.com/article/news/224076/the-periodic-table-of-pokemon/http://www.gamepro.com/article/news/224076/the-periodic-table-of-pokemon/
http://clockworkrealm.wordpress.com/2010/09/11/lolwut-periodic-tables/http://clockworkrealm.wordpress.com/2010/09/11/lolwut-periodic-tables/
http://www.rsc-northwest.ac.uk/acl/eMagArchive/RSCeMags2007/July07/012eMagazine/internet_periodic_table.htmlhttp://www.rsc-northwest.ac.uk/acl/eMagArchive/RSCeMags2007/July07/012eMagazine/internet_periodic_table.html
http://www.geekologie.com/2009/03/scientific-a-periodic-table-of.phphttp://www.geekologie.com/2009/03/scientific-a-periodic-table-of.php
http://clounaghscience.wordpress.com/elements-compounds-and-the-periodic-table/http://clounaghscience.wordpress.com/elements-compounds-and-the-periodic-table/
http://clockworkrealm.wordpress.com/2010/09/11/lolwut-periodic-tables/http://clockworkrealm.wordpress.com/2010/09/11/lolwut-periodic-tables/
Two kinds of Angular Momentum • Classical Angular Momentum • L = r x p • r vector, p vector L vector • L obeys vector math • Any L possible, no contraints on Lx Ly Lz • Quantum • Quantum Mechanical Angular Momentum • L = r x p • r vector, p vector operator L 3 component operator • L obeys …… got to be careful • L described by two labels l , m • L and Lz can be known, Lx and Ly cannot
Bohr Model of Ang Momentum Classical or Semi-classical description Note: s-states (l=0) have no Bohr model picture Eisberg & Resnick: Fig 7-11
Vector Model of QM Ang. Momentum quantum numbers E&R Fig 7-12
Edmonds“A.M. in QM” pg 19: “We might imagine the vector moving in an unobservable way about the z-axis...” pg 29: “The QM probability density, not being time dependent, gives us no information about the motion of the particle in it’s orbit.” Y*(r,t) Y(r,t) Y(r,t)=Y(r) e-iwt
Morrison, Estle, Lane “Understanding More QM”, Prentice-Hall, 1991
Addition of Orbital Angular Momentumfor two electrons L2 L1 Ltot = L1 + L2 Problem: Two objects each travel in a p-orbit ( l=1 ). What are the allowed values of ltot, mtot ? L1 Ltot L2
Addition of Angular Momentum www.bokerusa.com aligned configuration “aligned” does not mean straight jack-knife configuration www.cartowning.co.za/DBNRECGC.htm “jack-knife” does not mean antiparallel
Addition of Intrinsic SpinAngular Momentum Stot = S1 + S2 S1 S2 Because objects are all spin-1/2 stot = 0, 1 singlet triplet WARNING: CAN’T MAKE TRIPLET IF BOTH ELECTRONS ARE IN THE SAME ORBIT BECAUSE THEY WOULD BE IN THE SAME ms SUBSTATE. i.e. ms = + ½ and + ½
Total Angular Momentumfor a single electron L1 Jtot = L1 + S1 S1
Add It All Up for Two Electrons L2 L1 S2 S1 What is the “total” total angular momentum, Jtot ? LS Coupling JJ Coupling
Two Ways to Add • LS Coupling (aka Russell-Sanders Coupling) • Ltot = L1 + L2 and Stot = S1 + S2 • Jtot = Ltot + Stot • Preferred for lighter atoms, Z<30 • JJ Coupling • J1 = L1 + S1 and J2 = L2 + S2 • Jtot = J1 + J2 • Preferred for heavier atoms, where the nucleus has a lot of charge and creates big internal magnetic fields from the point of view of the electrons.
Hund’s Rules L2 • Hund observed in lighter atoms that • The S1 – S2 orientation energy is very strong • Bigger Stot have lower energy • The L1 – L2 orientation energy is not as strong • Bigger Ltot have lower energy • If shells are less than half full, smaller Jtot have lower energy L1 S2 S1 http://en.wikipedia.org/wiki/Friedrich_Hund 4 February 1896 - 31 March 1997
Multi-e Spectroscopic Notation QUANTUM NUMBERS principal: n ltot , stot jtot . stot = 1, ltot=0, jtot=1 3S1 Stot = S1 + S2 + … Ltot = L1 + L2 + … Jtot = Ltot + Stot
Where an individ electron is at n l j 1s1/2 2s1/2 2p1/2 2p3/2 A.M. for whole atom 2Stot+1LtotJtot 1S0 3S1 3P0 , 3P1, 3P2 Two Kinds of Spectroscopic Notation