Find the % by mass of oxygen if a compound is decomposed by an electric current giving 19.98 g O and 2.52 g H.

Non metal is an element or substance that is not a metal metal is a solid material that is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivitymetalloid is an element (e.g., germanium or silicon) whose properties are intermediate between those of metals and solid nonmetals. they are electrical semiconductors.

A.(nh4)(2co3)is the correct answer