A table of the relative abundance of elements shows that most of our universe is made up of Hydrogen and Helium

Relative Abundance of Selected Elements in the Universe (Si=1)

H 12,000
He 2,800
O16
N8
C3
Fe2.6
Si1
Mg0.89
S0.33
Ni0.21
Al0.09
Ca0.07
Na0.045
Cl0.025