Neon - Ne General Information Discovery Neon was discovered by Sir William Ramsay and M.W. Travers in London in 1898. Appearance Neon is a colourless, odourless gas. Source Neon is a rare gas present in the atmosphere to the extent of 1 part in 65,000 of air. It is obtained by liquefaction of air and separation from other elements by fractional distillation. Uses In a vacuum discharge tube neon glows a reddish orange colour, and is therefore used in making the ubiquitous neon advertising signs, which accounts for its largest use. It is also used to make high-voltage indicators, lightning arrestors, wave meter tubes and television tubes. Liquid neon is now commercially available and is finding important application as an economic cryogenic refrigerant, as it has over 40 times more refrigerating capacity per unit volume than liquid helium and more than 3 times that of liquid hydrogen. Biological Role Neon has no known biological role. It is non-toxic. General Information Natural neon is a mixture of three isotopes, but five other unstable isotopes are known. It is a very inert element. Neon is said to form a compound with fluorine but it is still questionable whether such a compound truly exists.

	Physical Information
	Atomic Number		10
	Relative Atomic Mass (12C=12.000)		20.180
	Melting Point/K		24.48
	Boiling Point/K		27.10
	Density/kg m-3		0.900 (gas, 273K)
	Ground State Electron Configuration		[He]2s22p6
	Electron Affinity(M-M-)/kJ mol-1		-99

	Key Isotopes
	nuclide	20Ne	21Ne	22Ne
	atomic mass	19.992	20.993	21.991
	natural abundance	90.51%	0.27%	9.22%
	half-life	stable	stable	stable

Other Information
Enthalpy of Fusion/kJ mol-1		0.324
Enthalpy of Vaporisation/kJ mol-1		1.736
Oxidation States
not applicable
Covalent Bonds /kJ mol-1
not applicable

	Ionisation Energies/kJ mol-1
	M - M+	2080.6
	M+ - M2+	3952.2
	M2+ - M3+	6122
	M3+ - M4+	9370
	M4+ - M5+	12177
	M5+ - M6+	15238
	M6+ - M7+	19998
	M7+ - M8+	23069
	M8+ - M9+	115377
	M9+ - M10+	131429