Final answer:
C₂O₄²⁻ is an ion, specifically a covalent substance, formed by the sharing of electrons between carbon and oxygen atoms. It has a molecular formula of CO₂²⁻.
Step-by-step explanation:
The molecule C₂O₄²⁻ is an ion. It consists of two carbon atoms bonded to four oxygen atoms, with an overall charge of -2.
The molecular formula for the ion is CO₂²⁻.
This molecule is a covalent substance. Covalent substances are formed by the sharing of electrons between atoms, and they typically have low melting and boiling points.