Physical Chemistry III
- Structure of Matter -

Discussion Fr 15.7.2005 10:30 - 11:15 am lecture hall SN 20.2

Problem Set 12 (ground state, excited states, term symbols, transition strength)

Problem 1

The electronical ground state configuration of mercury is [Xe](4f14)(5d10)(6s2). What is the term symbol of the ground state?
What term symbols are possible when a 6s electron is promoted to a 6p state ?
What term symbols are possible when a 5d electron is promoted to a 6p state ?
Which transitions are allowed?

Problem 2

The electron configuration of Ytterbium in the ground state is [Xe] (4f)14(6s)2. What term symbols are possible when a 4f electron is promoted to a 5d state: [Xe] (4f)13(6s)2(5d)?
Sort the resulting states in an energetic order assuming that (besides Hund's rules) the term with the highest orbital angular momentum has the lowest energy.

Problem 3

You measure the extinction of a molecule e [litre mol-1cm-1] in the visible range and observe ε= 20000dm³ mol-1cm-1 in the maximum of the absorption at 600 nm. The width of absorption is 24 nm.

1. Determine the differential cross section s(n).
2. Determine the integral cross section σo = òsdn . For simplicity assume that the integral is given by "width" * "high" of the absorption.
3. Determine the oscillator strength f of the transition.
4. Determine |Rnm|.

Problem 4

Two equivalent d electrons form the ground state of Ti, (3d)². What term values are possible under consideration of the Pauli principle (use the table in the script). Which terms become possible, when the states are formed with a 3d and a 4d electron (3d)1(4d)1?