8
Oxygen
Atomic Number8
Atomic Mass15.999 u
CategoryNonmetal
State at Room TempGas
Year Discovered1774
About Oxygen
The third most abundant element in the universe. Makes up 21% of Earths atmosphere and 65% of the human body by mass. Produced by photosynthesis in plants and cyanobacteria. Ozone in the upper atmosphere protects against UV radiation. Liquid oxygen is pale blue and slightly magnetic. Responsible for rust, fire, and most combustion reactions.
More Nonmetals
1
Hydrogen
Lightest element. Makes up 75% of all normal matter by mass. Stars are mostly hy...
6
Carbon
The basis of all known life. Forms more compounds than any other element, over 1...
7
Nitrogen
Makes up 78% of Earths atmosphere. Essential for amino acids, DNA, and proteins....
15
Phosphorus
Discovered by a German alchemist searching for the philosophers stone, made from...