Helium
Revision as of 19:50, 7 December 2011 by 210.177.210.61 (→3He)
Helium | |
---|---|
He | |
In situ availability: | trace |
Necessity: | |
Atomic number: | 2 |
Atomic mass: | 4.002602 |
group: | 18 |
period: | 1 |
normal phase: | Gas |
series: | Noble gases |
density: | 0.1786 g/L |
melting point: | 0.95K, -272.2°C, -458.0°F |
boiling point: | 4.22K, -268.93°C, -452.07°F |
N/A ← N/A → N/A | |
H ← He → N/A | |
F ← Ne → N/A | |
Atomic radius (pm): | 31 pm |
Bohr radius (pm): | |
Covalent radius (pm): | 32 |
Van der Waals radius (pm): | 140 |
ionic radius (pm): | - |
1st ion potential (eV): | 24.59 |
Electron Configuration | |
1s2 | |
Electrons Per Shell | |
2 | |
Electronegativity: | |
Electron Affinity: | Unstable anion |
Oxidation states: | - |
Magnetism: | |
Crystal structure: | Hexagonal or body centered cubic |
Helium is a component of the solar wind, and hence is one of the volatiles found (in parts per million level) in Lunar regolith. It is a Noble gas in group 18 and is the second element in the Periodic Table of the Elements. This element has two stable isotopes: 3 and 4.
The most common isotope, Helium-4, has a nucleus of two protons and two neutrons, and two electrons. The less common isotope Helium-3 has two protons and one neutron.
The paroagn of understanding these issues is right here!
Applications
- Medical Lung Imaging
- According to Wikipedia:
- http://en.wikipedia.org/wiki/Helium_3
- Details on this experimental application of He3: http://cerncourier.com/main/article/41/8/14
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