Chapter 8, Problem 8.93P

Interpretation Introduction

Interpretation:

The warm yellow color of gold is to be explained on the basis of the energy difference between $5d$ and $6s$ sublevels of gold $\left(2.7\text{eV}\right)$.

Concept introduction:

The color of the chemicals is a physical property that generally arises from the excitation of electrons due to the absorption of energy by the chemicals. All the atoms and molecules are capable to absorb and release energy in the form of photons. The amount of energy released or absorbed is the difference between the energies of the two sublevels.

The energy is proportional to the frequency and is expressed by the Plank-Einstein equation as follows:

$\text{E}=h\nu$

Here,

$\text{E}$ is the energy.

$h$ is the Plank’s constant.

$\nu$ is the frequency.

The equation to relate the frequency and wavelength of electromagnetic radiation is as follows:

$\nu =\frac{c}{\lambda }$

The equation to calculate the energy of a photon is,

$\text{E}=\frac{hc}{\lambda }$ (1)

Here,

$c$ is the speed of light.

$\lambda$ is the wavelength.