Chapter 20, Problem 20.7P

(a)

Interpretation Introduction

Interpretation:

Energy difference between the ground and excited state of $\text{Cu}$ has to be calculated.

Concept Introduction:

Planck’s hypothesis states energy difference associated with photon is as follows:

  $\Delta E=\frac{hc}{\lambda }$

Here,

$\lambda$ denotes wavelength.

$h$ denotes Planck’s constant

$c$ denotes speed of light.

$\Delta E$ denotes energy difference.

Boltzmann’s distribution law for relative population is as follows:

  $\frac{N*}{N_0}=\left(\frac{g*}{g}\right)e^{-\Delta E/kT}$

Here,

$N*$ denotes population of excited state.

$N_0$ denotes population in ground state.

$g*$ denotes degeneracy of excited state.

$g$ denotes degeneracy of ground state.

$k$ denotes Boltzmann’s distribution.

$T$ denotes temperature.

$\Delta E$ denotes energy difference.

(b)

Interpretation Introduction

Interpretation:

Ratio of $N*\text{/}{N}_0$ at $2400\text{ K}$ has to be calculated.

Concept Introduction:

Refer to part (a).

(c)

Interpretation Introduction

Interpretation:

Percent fraction change when temperature changes to $2415\text{ K}$ has to be calculated.

Concept Introduction:

Refer to part (a).

(d)

Interpretation Introduction

Interpretation:

Ratio of $N*\text{/}{N}_0$ at $\text{6000 K}$ has to be calculated.

Concept Introduction:

Refer to part (a).