Question

how do you know if something is saturated or unsaturated

Answer 1

Well unsaturated or saturated, is a way of referencing organic compounds. Saturated compounds usually don't have double bonds, and unsaturated compounds have double bonds. They're unsaturated because double bonds are far more reactive that single bonds, and thus can react with another species, forming a new single bond and saturating the compound.

Answer 2

saturated = single bonds
unsaturated = double bonds, and thus more chemically reactive.

Answer 3

triple bonds and double bonds are unsaturated. single bonds are saturated