What happened to heavier elements in Earth due to density-based differentiation?

Correct answer: They sank toward the center and helped form the core

The governing concept is density differentiation during the early development of Earth. When the young Earth was sufficiently hot and partly molten, materials could separate according to density. Heavy metallic elements, especially iron and nickel, moved downward under gravity toward the centre, while lighter silicate materials remained nearer the outside and contributed to the mantle and crust. Option B is correct because sinking dense matter helped establish the core and Earth’s layered internal structure. Option A is physically and geologically incorrect, C confuses solid planetary materials with surface water, and D mistakes physical separation for a transformation of matter into light.