Hydrogen atoms have a completely different set of orbits than other elements (Helium, Oxygen, Nitrogen, etc). By studying the Energy Level Diagram of different kinds of atoms, we can learn to identify unique sets of lines which identify a specific atom.

For instance, to identify the atoms found inside a hot glowing gas (such as a neon-like tube), we would use a prism to make a SPECTRUM, and look at the wavelength of the individual lines emitted. By looking for certain lines and patterns of lines, we can identify the atom present within the gas.