The most abundant element in the Earth's crust is oxygen, which makes up almost half or 46 percent of the mass of the Earth's crust. Oxygen is also the third most plentiful element in the universe and occupies about 21 percent of the planets atmosphere. The element oxygen is capable of combining with most elements and is a highly reactive non-metal gas at room temperature.
Oxygen has a melting point of -361.82 degrees F and a boiling point of 297.31 degrees F. It has a density of 0.001429 grams per cubic centimeter and an atomic weight of 15.9994. Oxygen is assigned the number 8, the period number 2 and belongs to group number 16 on the periodic table of elements.