Helium is the smallest and the lightest noble gas and one of the most unreactive elements, so it was commonly considered that helium compounds cannot exist...

gas compounds have been formed. Neutral compounds in which helium and neon are involved in chemical bonds have not been formed (although some helium-containing...

In chemistry, noble gas compounds are chemical compounds that include an element from the noble gases, group 18 of the periodic table. Although the noble...

Helium (from Greek: ἥλιος, romanized: helios, lit. 'sun') is a chemical element; it has symbol He and atomic number 2. It is a colorless, odorless, non-toxic...

can also be viewed as protonated helium. It is the lightest heteronuclear ion, and is believed to be the first compound formed in the Universe after the...

The helium dimer is a van der Waals molecule with formula He2 consisting of two helium atoms. This chemical is the largest diatomic molecule—a molecule...

Until the 1960s no noble gas compounds had been synthesized. Following the first successful synthesis of xenon compounds in 1962, synthesis of krypton...

Neon compounds are chemical compounds containing the element neon (Ne) with other molecules or elements from the periodic table. Compounds of the noble...

Disodium helide (Na2He) is a compound of helium and sodium that is stable at high pressures above 113 gigapascals (1,130,000 bar). It was first predicted...

Liquid helium is a physical state of helium at very low temperatures at standard atmospheric pressures. Liquid helium may show superfluidity. At standard...

noble gases, where the heavier ones are more reactive); and predicted helium compounds often lack neon analogues even theoretically, but sometimes have beryllium...

Hydrogen compounds are compounds containing the element hydrogen. In these compounds, hydrogen can form in the +1 and -1 oxidation states. Hydrogen can...

a curve that oscillates up and down about a dozen times. Helium compounds#Predicted compounds Tariq, Naima; Taisan, Nada; Singh, Vijay; Weinstein, Jonathan...

Helium-3 (3He see also helion) is a light, stable isotope of helium with two protons and one neutron. (In contrast, the most common isotope, helium-4...

Neon is a chemically inert gas, with no known uncharged neon compounds. Existing neon compounds are primarily ionic molecules or fragile molecules held together...

The helium trimer (or trihelium) is a weakly bound molecule consisting of three helium atoms. Van der Waals forces link the atoms together. The combination...

is −2 in almost all known compounds of oxygen. The oxidation state −1 is found in a few compounds such as peroxides. Compounds containing oxygen in other...

as methane. Hydrogen can form compounds with most elements and is present in water and most organic compounds. Helium (He) exists only as a gas except...

A helium atom is an atom of the chemical element helium. Helium is composed of two electrons bound by the electromagnetic force to a nucleus containing...

of carrier gas. Since most compounds have a thermal conductivity much less than that of the common carrier gases of helium or hydrogen, when an analyte...

A gas giant is a giant planet composed mainly of hydrogen and helium. Jupiter and Saturn are the gas giants of the Solar System. The term "gas giant" was...

chromatography used in analytical chemistry for separating and analyzing compounds that can be vaporized without decomposition. Typical uses of GC include...

the product was probably a mixture of several compounds, Bartlett's work was the first proof that compounds could be prepared from a noble gas. Since Bartlett's...

Helium-3 nuclear magnetic resonance (3He-NMR) is an analytical technique used to identify helium-containing compounds. Because a helium atom, or even...

Helium storage and conservation is a process of maintaining supplies of helium and preventing wasteful loss. Helium is commercially produced as a byproduct...

react to form compounds under some conditions. The inert gases are obtained by fractional distillation of air, with the exception of helium which is separated...

alkyl halides. Many other lithium compounds are used as reagents to prepare organic compounds. Some popular compounds include lithium aluminium hydride...

compounds, the chemical compounds that contain the element argon, are rarely encountered due to the inertness of the argon atom. However, compounds of...

state (25°C [77°F], 100 kPa) Melting point: helium does not solidify at a pressure of 1 atmosphere. Helium can only solidify at pressures above 25 atm...

74. It is a rare metal found naturally on Earth almost exclusively as compounds with other elements. It was identified as a distinct element in 1781 and...