Why is neon is called a noble gas?
Neon is a noble gas because it has a complete octat and it is stable in its ground state.
Neon is one of the noble gases - helium, neon, argon, krypton, xenon. Gas discharge lights, commonly called neon lights, will produce different colors depending on which gas is used. Neon itself produces an orange light. The Wikipedia entry ' Noble Gas' has a nice illustration near the end showing the colors produced by each of the above gases
The second noble gas is Neon (Ne). The noble gases are chemical elements with similar properties: they are odorless, colorless, monatomic gases with low chemical reactivity except under particular conditions. Neon has about 2/3 the density of air, it is chemically inert, and it forms no uncharged chemical copounds. It has a bright orange-red glow when placed in a high voltage electric field, which is why it is used in glow lamps or advertising signs.