Helium
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
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
n/a
Evaporation Heat(kj/mol)
0.08
Thermal Conductivity(@25°C W/m K)
0.152
Debye Temperature
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
