Introduction To Spectroscopy Introduction of Spectrophotometry Molecular Excitation and Spectroscopy Molecules are clusters of atoms that are held together by the sharing of electrons by the atoms within the molecule. These electrons are referred to as the bonding electrons.
Molecules are capable of absorbing energy.
This makes the molecules higher in energy than they would normally be. There normal energy state is called the ground state of the molecule. The molecule that has absorbed energy is said to be excited or perturbed . Excited molecules have a tendency to lose a portion or all of the energy that they absorbed in the first place. Instruments have been designed that will measure and record either the amount of energy absorbed or the amount of energy that the excited molecule releases in order to return to the ground state level.