Why do the terrestrial planets have a much higher fraction of their mass in heavy chemical elements (as opposed to lighter chemical elements) than the giant planets?
A) Terrestrial planets are low in mass and high in temperature, thus their lighter chemical elements eventually escaped to the outer reaches of the Solar System.
B) The heavier elements in the forming solar nebula sank to the center of the Solar System, thus the inner terrestrial planets formed mostly from heavy chemical elements.
C) The giant planets were more massive than terrestrial planets, and the giant planets preferentially pulled the lighter elements from the inner to the outer Solar System.
D) Terrestrial planets formed much earlier than giant planets before the hydrogen and helium had a chance to cool and condense onto them.
E) Terrestrial planets are colder and thus more massive chemical elements condensed on then than the giant planets.

Question

Quizplus · Accepted Answer

Terrestrial planets, being closer to the Sun, were hotter and had lower gravity, causing lighter elements like hydrogen and helium to escape, leaving them with a higher fraction of heavier elements.

Why Do the Terrestrial Planets Have a Much Higher Fraction