Question

1. (2pt) Explain the mechanism by which atoms absorb light, i.e. what happens when an atom absorbs a photon. 2. (2pt) Why do atomic emission spectra come in the form of lines instead of broad bands that span whole regions of the electromagnetic spectrum?

Answer 1

When an atom absorbs energy the atom jumps from its ground state to the excited state. Ground state is the most stable and lowest energetic state of an atom where the excited states is the higher energetic states. In ground state the electrons of an atom is arranged by the rules of aufbau's principle, Pauli's exclusion principle and Hund's multiplicity principle. So when it absorbs some radiation one of more electrons from its valence shell get excited and it goes to higher orbits.

n=3 — . n=2 — n=0-0 0 0