The contents of two petri dishes are described in the table. Contents of Petri Dishes
Petri Dish Contents Final State of the Substance
C elemental sulfur fine yellow colored powder
D compound sodium chloride white colored cubic crystals

Based on the final state, which statement is true about the substances in the petri dishes?
The final substances in both petri dishes are mixtures.
The final substances in both petri dishes are pure substances.
The final substance in Petri dish C is a pure substance and in Petri dish D is a mixture.
The final substance in Petri dish C is a mixture and in Petri dish D is a pure substance.

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3

the answer is b because, investigating whether another species of moth also drinks tears might be interesting, but it would not directly explain why this species of moth does.

to explain why this species of moth drinks tears, the scientist could ask: "what nutrients that moths need are in elephant tears? "

the scientist could experiment with moth repellent or oter ways to keep the moths away, but that would not answer his original question.