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.
gold and platinum
glass and charcoal
gold, platinum, glass and charcoal
gold and charcoal
none of the above