Classify the substances as atomic elements, molecular elements, molecular compounds, or ionic compounds. CO2, HCl, Al2S3, Cd, F2,Ag,O2,NaCl

Answer 1

what don't you understand?

Surely you can at least pick out the elements, and then see which are atoms and which are molecules.

And take a stab at the compounds; the ionic ones usually involve a metal and a halogen.