The chemical formula of oxygen is o2 that means it is a single compound or molecule gas? it is pure substance or mixture?

Acandle’s wick is the fabric string that holds the flame, and it burns down at a constant slow pace when the candle is lit. the wick is usually surrounded by wax. which is the most important property of covalent compounds that makes them useful for making candle wax? a low boiling point a low melting point a high boiling point a high melting point