Answer to Question #207344 in Electric Circuits for BADAU

Question

What is the difference between emission and absorption spectra? [2] (b) Name two applications of emission and absorption spectra. [2] (c) Describe how the absorption and emission spectra of the gases in the atmosphere give rise to the Greenhouse Effect

Answer 1

Emission spectrum is the spectrum produced by a gaseous substance when its particles are in excited states. Absorption spectrum can be produced by a light passed through a gaseous substance.

The key difference between emission and absorption spectra: their appearance can be illustrated by the following example. Imagine a continuous spectrum - a stripe colored in rainbow colors. If we 'subtract' absorption spectrum, we get emission spectrum. If we subtract the emission spectrum from the continuous spectrum, we get absorption spectrum.

The two applications: absorption and emission spectroscopy is used to establish the presence of certain chemicals in a substance. In astronomy it allows establishing the composition of planets and stars.

Greenhouse effect: the greenhouse gases absorb infrared (thermal) radiation, which prevents the heat from leaving the planet, so, the greenhouse gases warm up the planet.