Lecture 8 (Character Tables, Polyatomic Molecules, etc.)

Question 1

What axis coincides with the principal axis?

Answer 1

the z axis

Question 2

what does the symmetry labels “A” and “B” mean about the degeneration?

Answer 2

A and B indicate non-degenerate

Question 3

What does A indicate with respect to rotation and the principle axis?

Answer 3

symmetric

Question 4

What does B indicate with respect to rotation and the principle axis?

Answer 4

anti-symmetric

Question 5

What is the degeneration of E?

Answer 5

doubly-degenerate

Question 6

What is the degeneration of E?

Answer 6

doubly-degenerate

Question 7

What is the degeneration of T?

Answer 7

triply-degenerate

Question 8

What does ‘ indicate with respect to σh?

Answer 8

symmetric

Question 9

What does “ indicate with respect to σh?

Answer 9

anti-symmetric

Question 10

What does g indicate with respect to inversion?

Answer 10

symmetric

Question 11

What does u indicate with respect to inversion?

Answer 11

anti-symmetric

Question 12

What does 1 indicate with respect to rotation about the C2 secondary axis, or σv if no C2 is present?

Answer 12

symmetric

Question 13

What does 2 indicate with respect to rotation about the C2 secondary axis, or σv if no C2 is present?

Answer 13

anti-symmetric

Question 14

What is the reduction formula?

Answer 14

ai: 1/g x (SUM(nR x X(R) x X (IR))

Question 15

What is convention in MO theory?

Answer 15

Upper case is used for symmetry labels and lower case is for orbitals of a given symmetry

Question 16

What is photoelectron spectroscopy?

Answer 16

electrons are ejected from individual molecules by high energy monochromatic radiation in a high vacuum.

Question 17

What is the difference between measured KE of an ejected electron and the energy of the incident photons?

Answer 17

The energy required to remove the electron from the molecule