Elements can be diagonsed by

Element analysis by Atomic Emission Spectroscopy. These wavelength bands or emission lines form a pattern that is characteristic of the atom that produced it. Generally, the intensities of the various emission lines are proportional to the number of atoms in the test sample that produced the lines. When an atom absorbs energy, its electrons jump to higher energy levels. Each transition has a specific energy difference. This collection of transitions makes up an emission spectrum. These emission spectra are as distinctive to each element as fingerprints are to people.