Properties Of Helium-3 Isotope:
|Properties of Helium-3 Isotope||HELIUM-3|
|Neutron Number (N)||1|
|Atomic Number / Proton Number (Z)||2|
|Mass Number / Nucleon Number (A)||3|
|Natural Abundance (%)||0.000137|
|Atomic Mass (Da)||3.01602932|
|Relative Isotopic Mass||3.01602932|
|g-factor (g value)||-4.25499544|
|Electron Configuration Block||s|
|Melting Point (K)||0.95|
|Boiling Point (K)||4.222|
|Heat of Formation||―|
|Dipole Polarizability ||1.38375|
|Electron Affinity (kJ/mole)||-0.5|
|Electronegativity (Pauling scale)||0|
|Atomic Radius (pm)||0|
|Covalent Radius (pm)||120|
|VDW Radius (pm)||140|
Helium is a colourless, odourless gaseous nonmetallic element. It belongs to group 18 of the periodic table. This element has the lowest boiling point of all elements and can only be solidified under pressure. Within the eighteenth group, helium is on the second place in the earth's crust (after argon). Helium is chemically inert, no known compounds. It was discovered in the solar spectrum in 1868 by Lockyer.
It is interesting to know the ending "um" (Helium) characteristic of metals was used in the element name as Lockier assumed that the element he discovered was a metal. By analogy with other noble gases, it would be logical to give him the name "Helion". In modern science, the name "helion" is attached to the nucleus of the light helium isotope helium-3.
Helium is named after the Greek Titan of the Sun, Helios.
Most of the earth's helium present today is created by the natural radioactive decay of heavy radioactive elements (thorium and uranium although there are other examples), since the alpha particles emitted by such decays are composed of helium-4 nuclei.
Helium is used in balloons, deep sea diving and welding. It is also used in very low temperature research. Helium is a convenient indicator for geologists. Leak detection is one of the industrial applications of helium. Since helium diffuses through solids three times faster than air, it is used as an indicator gas for detecting leaks in high-vacuum equipment (such as cryogenic tanks) and high-pressure containers. Helium mixtures, such as trimix, heliox and heliair, are used for deep immersion, since helium does not have narcotic properties as a breathing gas. Such mixtures reduce the effect of narcosis which intensifies with increasing depth. When mixed with a heavier gas such as xenon, helium is useful for thermoacoustic cooling due to its low Prandtl number and high heat capacity coefficient.
back to Helium isotope list