(An element with an abundance of 11 is one-tenth as common as hydrogen; if 10, it is one-hundredth as common; and so on.) In 1989, the standard oxygen abundance was 8.93, which meant there were ...

On Earth, oxygen is the most abundant in both the crust (46 percent) and the ocean (86 percent). Elements 91, protactinium, and 85, astatine, are among the rarest on the planet—Earth’s total reserves ...

It is the most abundant element in the universe, making up 75% of normal matter by mass and more than 90% by number of atoms. Life cannot exist without hydrogen, because it is in nearly all of the ...