Chapter 28.1, Problem 10SSC

To determine

To Explain: The way, absorption spectrum of a gas can be determined.

To Describe: The reasons for the spectrum’s appearance.

Explanation of Solution

Introduction:

When light passes through a cold gas, some of the wavelengths are absorbed by it and thus, spectrum of such a gas is absorption spectrum. The absorbed wavelengths correspond to the difference in the energy level to which the atoms of the gas jump to from its initial state by absorbing photons. The absorption spectrum of gas provides the information about its composition. This is because, each element has specific allowed energy levels and thus, have unique spectrum.

An absorption spectrum appears to have dark bands over a colored background. These dark bands correspond to absorbed wavelengths of light.