Helium

Helium is a chemical element with atomic number 2 and the symbol He

It is a colorless, odorless, inert and monatomic gas.
And is the first in the noble gas group in the periodic table.

It is the second lightest atom.

Helium is composed of two electrons in atomic orbitals
surrounding a nucleus which has two protons and (usually) two neutrons.

Heliums melting point is −272.20 °C
And it's boiling point is −268.928 °C

Isotopes:
-There are nine known isotopes of helium, but only helium-3 and helium-4 are stable.

Forms:
-Normal helium at standard temperatures and pressures
-Solid helium
  At 25 atmospheres of pressure helium is a solid at 0.95 K
  And helium could also be made solid at room temperature if the pressure rises to about 114 thousand atmospheres
-Helium I
  Below its boiling point of -268,93 celcius and above the lambda point of
  -270,97 celcius, the isotope helium-4 exists in a normal colorless liquid state.
-And Helium II
  Liquid helium below its lambda point is called helium II

Uses:
Liquid helium is used in cryogenics, particularly in the cooling of
superconducting magnets.
Helium is used as a shielding gas in arc welding processes on materials
that at welding temperatures are contaminated and weakened by air or nitrogen.
Helium–neon lasers, a type of low-powered gas laser producing a red beam.
Helium is also used as a heat-transfer medium in some gas-cooled nuclear reactors.
Helium, when mixed with a heavier gas like xenon, is useful for thermoacoustic refrigeration.
Helium is also used in some hard disk drives.
One industrial use for helium is leak detection.
Because helium is lighter than air, helium can be used for lift through inflating something it can lift.
And it exhibits a red orange glow when placed in an electric field.