Answer:
The answer is oxygen.
Step-by-step explanation:
Oxygen is considered a chemical element that has the symbol O. In terms of mass, oxygen is considered one of the most abundant elements related to the universe. The other two are hydrogen and helium. It is said that the element was discovered by Carl Wilhelm Scheele about 1773, as well as Joseph Priestley in 1774.
Two atoms of this element are connected to form dioxygen. This is considered a diatomic gas. This is colorless as well as odorless. Diatomic oxygen gas establishes 20.8% concerning Earth's atmosphere.