Neon is the noble gas with atomic number 10. Its atomic number means that every neutral neon atom has 10 protons in its nucleus and, ordinarily, 10 electrons surrounding it.
Neon belongs to Group 18 of the periodic table, the family known as the noble gases. Its full electron arrangement fills the first two electron shells, leaving no strong tendency to form ordinary chemical bonds. That is why neon is colorless, odorless, and chemically inert under standard conditions.
British chemist and physicist William Ramsay and Morris Travers discovered neon in 1898 while separating liquefied air. The name comes from the Greek word neos, meaning “new.” Its brilliant red-orange glow in electrical discharge tubes soon made it famous in advertising signs, although many modern “neon” signs use other gases for different colors.
A common mix-up is with helium, which has atomic number 2, and argon, which has atomic number 18. Xenon is also a noble gas, but its atomic number is 54.