Chemistry

A compound is a pure substance which is made up of two or more elements.

Carbon dioxide (CO2) is a compound, because it is a pure substance which is made up of two elements, carbon and oxygen.

Water (H2O) is also a compound, because it is a pure substance which is made up of two elements, hydrogen and oxygen.

Compound means substance that formed by two or more elements combined chemically. (like different kinds of bonds)

So,
Both carbon dioxide and water are compound, with the fomula CO2 and H2O

And, both of them are covalent compound, which have a simple molecular structure.


2010-11-16 18:43:35 補充：
Sorry, not "covalent compound"


BUT


"MOLECULAR compound"

Yes , they are compounds by defination of compound-- two or more elements form chemically a new substance .