Classify as element, compound, or mixture: a. Lump of copper, Cu b. gravel, and sand
c. stick of margarine (water + oil) d. lump of sugar C12, H22, O11
e. an oil slick on water f. ozone, O3

It has to be b i hope this

Fine out you self hx

It is a mixture. simply put, a compound must be pure, that is, of only one chemical structure and composition. a mixture is made of different chemical substances (i.e. elements, molecules, compounds) that are not chemically bonded to each other, but instead physically grouped together, as in the case of gasoline (a homogeneous solution).