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Helium

2
He
4.00260
Helium
 General | States | Energies | Oxidation & Electrons | Appearance & Characteristics | Reactions | Other Forms Radius | Conductivity | Abundance

General:

Name: Helium Symbol: He
Group: Noble Gas Atomic weight: 4.00260
Density @ 293 K: 0.0001787 g/cm3 Atomic volume: ?
Group: Noble Gas discovered: 1895

States:

state (s, l, g): g
melting point: K boiling point: 4.2 K
Heat of fusion: ? Heat of vaporization: 0.0845 kJ/mol

Energies:

1st ionization energy: 2372.3 kJ/mole
electronegativity: 2nd ionization energy: 5250.3 kJ/mole
electron affinity: 0 kJ/mole 3rd ionization energy: kJ/mole
Specific heat: 5.193 J/gK heat atomization: 0 kJ/mole atoms

Oxidation & Electrons:

Shells: 2 electron configuration: 1s2
minimum oxidation number: 0 maximum oxidation number: 0
min. common oxidation no.: 0 max. common oxidation no.: 0

Appearance & Characteristics:

structure: color: colorless
uses: cryogenics, blimps toxicity: no
hardness: mohs characteristics: Inert, dens

Reactions:

reaction with air: none
reaction with 6M HCl: none reaction with 6M HCl: none
reaction with 15M HNO3: none reaction with 6M NaOH: none

Other Forms:

number of isotopes: 2 hydride(s): none
oxide(s): none chloride(s): none

Radius:

ionic radius (2- ion): pm ionic radius (1- ion): pm
atomic radius: 31 pm ionic radius (1+ ion): pm
ionic radius (2+ ion): pm ionic radius (3+ ion): pm

Conductivity:

thermal conductivity: 0.15 J/m-sec-deg
electrical conductivity: 1/mohm-cm polarizability: 0.198 A^3

Abundance:

source: Natural gas, air
rel. abund. solar system: 9.435 log abundance earth's crust: -2.1 log
cost, pure: 5.2 $/100g cost, bulk: $/100g