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The noble gases have also been referred to as inert gases, but this label is deprecated as many noble gas compounds are now known. [6] Rare gases is another term that was used, [ 7 ] but this is also inaccurate because argon forms a fairly considerable part (0.94% by volume, 1.3% by mass) of the Earth's atmosphere due to decay of radioactive ...
Because of its scarcity, xenon is much more expensive than the lighter noble gases—approximate prices for the purchase of small quantities in Europe in 1999 were 10 €/L (=~€1.7/g) for xenon, 1 €/L (=~€0.27/g) for krypton, and 0.20 €/L (=~€0.22/g) for neon, [67] while the much more plentiful argon, which makes up over 1% by volume ...
The heavier alkaline earth metals react more vigorously than the lighter ones. [2] The alkaline earth metals have the second-lowest first ionization energies in their respective periods of the periodic table [4] because of their somewhat low effective nuclear charges and the ability to attain a full outer shell configuration by losing just two ...
Helium is the second least reactive noble gas after neon, and thus the second least reactive of all elements. [95] It is chemically inert and monatomic in all standard conditions. Because of helium's relatively low molar (atomic) mass, its thermal conductivity , specific heat , and sound speed in the gas phase are all greater than any other gas ...
The noble gases (helium, neon, argon, krypton, xenon and radon) were previously known as 'inert gases' because of their perceived lack of participation in any chemical reactions. The reason for this is that their outermost electron shells (valence shells) are completely filled, so that they have little tendency to gain or lose electrons.
For example, N 2, the diatomic form of nitrogen, is used as an inert gas in situations where using argon or another noble gas would be too expensive. Formation of multiple bonds is facilitated by their five valence electrons, as the octet rule permits a pnictogen to accept three electrons on covalent bonding.
Two-phase detectors containing argon gas are used to detect the ionized electrons produced during the WIMP–nucleus scattering. As with most other liquefied noble gases, argon has a high scintillation light yield (about 51 photons/keV [ 39 ] ), is transparent to its own scintillation light, and is relatively easy to purify.
Each of these elements has two valence electrons in the outermost s-orbital (valence electron configuration ns 2), which is easily lost in chemical reactions to form the +2 oxidation state: thus the alkaline earth metals are rather reactive elements, with the exception of beryllium due to its small size.