65) Given the following list of densities, which materials would float in a molten vat of lead
provided that they do not themselves melt? Densities (g/mL): lead = 11.4, glass = 2.6, gold =
19.3, charcoal = 0.57, platinum = 21.4.
A) gold and platinum
B) glass and charcoal
C) gold, platinum, glass and coal
D) gold and charcoal
E) none of the above
66) A popular science demonstration is to take several liquids that will not mix together and
“stack” these liquids in a tall glass cylinder. Suppose the following three liquids were placed in
the same tall, narrow glass cylinder:
These liquids would stack in which order?
A) corn syrup on top, motor oil in the middle, vinegar on the bottom
B) vinegar on top, motor oil in the middle, corn syrup on the bottom
C) motor oil on top, corn syrup in the middle, vinegar on the bottom
D) corn syrup on top, vinegar in the middle, motor oil on the bottom
E) motor oil on top, vinegar in the middle, corn syrup on the bottom