Element Electron Orbitals/Emission Spectrum Common Compound(s)/Application(s)
2
Helium (He)
~/Balloons, Helium-Neon Laser (for Reading Bar Codes etc), Cooling (in Telescopes, Superconducting Magnets)
10
Neon
(Ne)
~/Light Signs
18
Argon
(Ar)
~/Incandescent Bulbs, Geiger Counter Probe
36
Krypton (Kr)
~/High-end Incandescent Bulbs
54
Xenon (Xe)
~/High-end Incandescent Bulbs, Projector Lamps, Strobe Lamps, Flashy Car Head Lamps
86
Radon
(Rn)

Group 18 Elements