Noble gas with one half-filled p-orbital from each F atom, resulting in a filled bonding orbital, a filled non-bonding orbital, and an empty antibonding orbital. The highest occupied molecular orbital is localized on the two terminal atoms. This represents a localization of charge which is facilitated by the high electronegativity of fluorine. The chemistries of the heavier noble gases, krypton and xenon, are well established. The chemistry of the lighter ones, argon and helium, is still at an early stage, while a neon compound is yet to be identified. The abundances of the noble gases in the universe decrease as their atomic
Atmosphere of Mars of free oxygen, carbon monoxide, water and methane, among other gases, for a mean molar mass of 43.34 g/mol. There has been renewed interest in its composition since the detection of traces of methane in 2003 that may indicate life but may also be produced by a geochemical process, volcanic or hydrothermal activity. The atmosphere is quite dusty, giving the Martian sky a light brown or orange-red color when seen from the surface; data from the Mars Exploration Rovers indicate suspended particles of roughly 1.5 micrometres in diameter. On 16 December 2014, NASA reported detecting an unusual increase, then decrease,