Atom
Name
Helium
IUPAC name
Helium
InChI
InChI=1S/He
InChI key
SWQJXJOGLNCZEY-UHFFFAOYSA-N
CAS number
7440-59-7
Comments
natural He, 99.9999% 4He
Symbol and fundamental properties
Symbol
He
Formula
$He$
Charge
0
Atomic number Z
2
Molar mass
4.002602 $g/mol$
State STP
gas
Electronegativity
0.0
Isotope mixture type
terrestrial abundance
Isotopes
  IUPAC Name A Mole fraction
Helium-3 3 1.34e-06
Helium-4 4 0.99999866
Type K
Energy (keV) 0.0246