Why the planets like earth are Mae up of heavy rocky materials?

Planets like Earth are composed of heavy rocky materials due to their formation in the inner solar system, where temperatures were high enough to prevent lighter gases from condensing. During the early solar system's formation, heavier elements like iron, silicon, and magnesium accumulated through processes like accretion and differentiation. This led to the creation of terrestrial planets with solid surfaces. Additionally, gravitational forces allowed these materials to coalesce, forming dense, rocky bodies that could support geological activity.