Helium

Category: noble gas
Atomic number: 2
Atomic weight: 4.002602
Phase: gas

Helium is name after the Greek God of the sun, Helios. It was detected as an unknown yellow spectral line in sunlight during a solar eclipse and through smoky London. Helium was formed in the big bang along with hydrogen and lithium. After hydrogen, helium is the second most abundant element in the universe, making 23 per cent of its mass.

Helium is an odorless, colorless gas that have very low chemical reactivity. Its outer shell is full of electrons (2), so it has little tendency to interact with other elements. It is a member of the ‘noble’ gases due to the fact that does not interact with other ‘riff-raff’ elements.

The main use of Helium is cryogenics, cooling the superconducting magnets in MRI scanners used in medicine. Liquid Helium at -269 C cools the magnets required to produce an intense magnetic field. The radio waves within the magnetic field interact with the hydrogen in the body’s molecules giving a picture of internal anatomy.

One of helium isotopes, Helium-3, has the potential to be use as a safe and environmentally friendly fuel. This isotope is rare on Earth but plentiful on the Moon. NASA wants to establish a Moon base to mine Helium to be use as fuel for fusion reactors.