Note that when the electron is in the n=1 level, it is then in the ground state. This electron has the minimum amount of energy possible.
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.
For a tutorial on spectral lines, go HERE or just to see examples of spectra of gas discharge tubes,go HERE. Colors