Pluto's density is 1.8 g/cm³.Iron has a density of about 5 g/cm³.Rock (e.g.basalt)has a density of about 3 g/cm³.Ice and water have densities of 1.0 g/cm³.Which of the following can be deduced from those densities?
A)Pluto has a large iron-nickel core.
B)Pluto is about one-third water and two-thirds rocky material.
C)Pluto is solid rock all the way through.
D)Pluto is composed entirely of water or water ice.

Question

Quizplus · Accepted Answer

Pluto's density is less than that of rock but greater than that of ice/water. This suggests that Pluto is made up of a combination of rock and ice/water, with the ratio being approximately 2:1 (two-thirds rocky material and one-third water/ice). It cannot be deduced that Pluto has a large iron-nickel core or is composed entirely of water/ice, as its density does not match those of these materials. It also cannot be deduced that Pluto is solid rock all the way through, as its density suggests the presence of some lighter elements like ice/water.

Pluto's Density Is 1