What is referred to by 'a scum'?

Based on the clue 'a sculpture head shoulders above the rest or slan...', what is the answer? Based on the clue 'a sculpture made from a mold perhaps of a broken a...', what is the answer? Based on the clue 'a sculpture of this heavyweights fist was donated ...', what is the answer? What is associated with: a sculpture titled this energy was unveiled at the u of chicago in 1967 exactly 25 years after… What is associated with: a sea chanty that became a hit in 1891 asked what shall we do with one of these? Based on the clue 'a sea creature scoot up', what is the answer? Based on the clue 'a sea once covered most of the midwest aquatic din...', what is the answer? Based on the clue 'a sea wasp is not an insect but one of these sting...', what is the answer?