(inorganic chemistry, organic chemistry) The derivative of arsine H₃As=O, or its organic derivatives.

(physics, astronomy) The nucleosynthesis process, subsequent to carbon burning, in which neon disintegrates to oxygen which subsequently fuses to form silicon, phosphorus sulfur and other elements of atomic number up to 40.

(physics, astronomy) A group of nuclear reactions, that involve the interaction of protons with carbon, nitrogen and oxygen nuclei, thought to be the main source of energy in main-sequence stars of greater than 1.4 solar mass.

(chemistry) any compound having the general formula R₃P=O <=> R₃P⁺O⁻

(inorganic chemistry) The compound boron trioxide.

(chemistry) a white, powdered alkali, Li₂O, used in the manufacture of glass and ceramics

(inorganic chemistry) A white, crystalline compound, BeO, used in semiconductors and in specialist ceramic applications.

an oxidizing agent

The process of reacting or treating something with oxygen.

carbon monoxide / carbon dioxide / carbon suboxide