Physical Properties of Helium

History

(Gr. helios, the sun). Janssen obtained the first evidence of helium during the solar eclipse of 1868 when he detected a new line in the solar spectrum. Lockyer and Frankland suggested the name helium for the new element. In 1895 Sir William Ramsay in Scotland discovered helium in the uranium mineral clevite while it was independently discovered in cleveite by the Swedish chemists P.T. Cleve and Nils Langlet at about the same time. I like to share this Formula for Buoyancy with you all through my article.

Rutherford and Royds in 1907 demonstrated that alpha particles are helium nuclei.

Properties

Helium has the lowest melting point of any element and is widely used in cryrogenic research because its boiling point is close to absolute zero. Also, the element is vital in the study of superconductivity.

Using liquid helium, Kurti and co-workers and others, have succeeded in obtaining temperatures of a few microkelvins by the adiabatic demagnetization of copper nuclei.

It has other peculiar properties. Helium is the only liquid that cannot be solidified by lowering the temperature. It remains liquid down to absolute zero at ordinary pressures, but it can readily be solidified by increasing the pressure. Solid 3He and 4He are unusual in that both can be changed in volume by more than 30% by applying pressure. Having problem with Large Rare Earth Magnets keep reading my upcoming posts, i will try to help you.

The specific heat of helium gas is unusually high. The density of helium vapor at the normal boiling point is also very high, with the vapor expanding greatly when heated to room temperature. Containers filled with helium gas at 5 to 10 K should be treated as though they contained liquid helium due to the large increase in pressure resulting from warming the gas to room temperature.

While helium normally has a 0 valence, it seems to have a weak tendency to combine with certain other elements. Means of preparing helium diflouride have been studied, and species such as HeNe and the molecular ions He+ and He++ have been investigated.
Helium is the chemical element with atomic number 2 and an atomic weight of 4.002602, which is represented by the symbol He. It is a colorless, odorless, tasteless, non-toxic, inert monatomic gas that heads the noble gas group in the periodic table. Its boiling and melting points are the lowest among the elements and it exists only as a gas except in extreme conditions. Next to hydrogen, it is the second most abundant element in the universe, and accounts for 24% of the elemental mass of our galaxy.