The chemical composition of the repeat unit for nylon 6,6 is given by the formula c12h22n2o2. atomic weights for the constituent elements are ac = 12, ah = 1, an = 14, and ao = 16. according to this chemical formula (for nylon 6,6), the percent (by weight) of carbon in nylon 6,6 is most nearly:

Consider a culture medium on which only gram-positive organisms such as staphylococcus aureus colonies can grow due to an elevated nacl level. a yellow halo surrounds the growth, indicating the bacterium fermented a sugar in the medium, decreasing the ph as a result and changing the color of a ph indicator chemical. this type of medium would be referred to as a differential and enrichment culture.