writing, chemistry

Photochemistry Assignment #4

This assignment covers material from Chapter 2 section 22 to Chapter 2 Section 37.

1) Spin corresponds to the ________________________ angular momentum of an electron.

2) Electron spin, like electron exchange, is fundamentally a quantum mechanical phenomenon that has no classical analogue. However, like a classical charged particle spinning on an axis, an electron has a magnetic moment (µ). Although a classical spinning electron would possess a continuous range of angular momentum values, quantum mechanics demands that an individual electron has a spin that has a fixed and fundamental value of exactly __________ .

3) Physical quantities that require both a magnitude and direction in order to be fully defined are called what?

4) Let the spin quantum number of some system be 3/2.

(a) What is the magnitude of the spin angular momentum vector? In other words, what

is S r

?

(b) How many possible values of MS are there (the spin multiplicity)?

(c) What are the values of MS?

(d) What are the values of the polar angle θ? In other words, what are the possible

values of the angle that S r

makes with the z-axis?

5) What is the origin of the term “triplet state”?

6) According to the uncertainty principle of quantum mechanics, if the value of SZ on the z-axis is measured precisely, then the azimuthal angle’s position in space will be

____________________________________________________ .

7) (a) The magnetic energy resulting from the interaction of a magnetic moment µ and an applied field HZ is known as what?

(b) The splitting of the energy into two or more levels when a molecular system is placed in an applied external magnetic field is known as the effect.

8) (a) The magnitude of the exchange interaction J is typically much ____________ than that of magnetic interactions. (b) What are the typical values of each?