ELEMENT ABUNDANCE
ABUNDANCE
(percentage of total number of
atoms) (percentage of total mass)
Hydrogen
91.2
71.0
Helium
8.7
27.1
Oxygen
0.078
0.97
Carbon
0.043
0.40
Nitrogen
0.0088
0.096
Silicon
0.0045
0.099
Magnesium 0.0038
0.076
Neon
0.0035
0.058
Iron
0.0030
0.14
Sulfur
0.0015
0.040