Why is it that the metallic core of a rocky body such as Earth is primarily composed of iron and not some denser material such as gold?  A. Iron forms clumps due to extra-cellular polymeric substances and planets then form around these clumps.  B. Gold has been extensively mined by humans so it is now depleted from the core.  C. The heavier elements such as gold have much lesser cosmic abundances than iron, iron is more than 1 million times more abundant in the universe  D. Iron is very strong, so it resists the impacts common in turbulent early solar systems, thus forming the cores of planets.

32) Why is it that the metallic core of a rocky body such as Earth is primarily composed of iron and not some denser material such as gold? 

A. Iron forms clumps due to extra-cellular polymeric substances and planets then form around these clumps.

 B. Gold has been extensively mined by humans so it is now depleted from the core.

 C. The heavier elements such as gold have much lesser cosmic abundances than iron, iron is more than 1 million times more abundant in the universe

 D. Iron is very strong, so it resists the impacts common in turbulent early solar systems, thus forming the cores of planets.