Neon is a chemical element with symbol Ne and atomic number 10. It is in group 18 (noble gases) of the periodic table. Neon is a colorless, odorless monatomic gas under standard conditions, with about two-thirds the density of air. It was discovered (along with krypton and xenon) in the summer of 1898 as one of the three residual rare inert elements remaining in dry air, after nitrogen, oxygen, argon and carbon dioxide are removed. Neon was the second of these three rare gases to be discovered, and was immediately recognized as a new element from its bright red emission spectrum. Neon's name is derived from Greek words meaning 'new one.' Neon is chemically inert and forms no uncharged chemical compounds. During cosmic nucleogenesis of the elements, large amounts of neon are built up from the alpha-capture fusion process in stars.