Plastics and polysaccharides are somewhat similar because they are both polymers. Polymers are a long chain of repeating units called monomers. Their difference, however, is the identity of their monomers. Plastics have hydrocarbons as monomers. Plastics with the monomer ethene is called polyethylene. For polysaccharides, their monomers are simple sugars.
(3 grams of carbon) x (1 mole of carbon/12 grams ) =3/12 = 1/4 of a mole of carbon. Then... ( 1/4 of a mole) x (6.02 x 10^23 atoms/mole) = approximately 1.5 x 10^23 atoms.
