Cite

Helium

He Helium
2
4.002602
1
Symbol
He
Atomic Number
2
Atomic Weight
4.002602
Element Classification
Discovered By
Sir William Ramsey, Nils Langet, P.T.Cleve
Discovery Date
1895 (Scotland/Sweden)
Name Origin
Greek: helios (sun).
Density (g/cc)
0.147 (@ -270�C)
Melting Point (K)
0.95
Boiling Point (K)
4.216
Appearance
Inert, colorless, odorless, tasteless gas
Atomic Radius (pm)
0.0
Atomic Volume (cc/mol)
31.8
Covalent Radius (pm)
n/a
Ionic Radius
93
Specific Heat
5.188
Fusion Heat (kJ/mol)
n/a
Evaporation Heat (kJ/mol)
0.08
Thermal Conductivity (@25°C W/m K)
0.152
Debye Temperature (K)
n/a
Pauling Negativity Number
n/a
First Ionizing Energy (kJ/mol)
2361.3
Oxidation States
n/a
Electronic Configuration
1s2
Lattice Structure
Hexagonal(HEX)
Lattice Constant
3.570
Lattice C/A Ratio
1.633

KEY

SEE ALSO

Helium

Columbia Encyclopedia

PREVIOUS

(H)

NEXT

(Li)