What is the most common type of element?
Hydrogen is the most common element in the universe.
About 91 % of the atoms in the universe are hydrogen atoms.
However, they are so light that they make up only 70.6 % of the mass of the universe.
Note that the vertical axis in the graph is logarithmic. Thus, hydrogen is about 10 times as abundant as helium.
The most abundant element on Earth is oxygen.
It accounts for 46.7 % of the mass and 48.2 % of the atoms in the Earth's crust.