Why is the earth’s core made up mainly of iron while the crust contains mostly silicate minerals? a. because iron melts and silicate minerals do not b. because iron is less dense than silicate minerals c. because silicate minerals melt and iron does not d. because iron is denser than silicate minerals

Correct
"D. because iron is denser than silicate minerals"

Considering the formation of the Earth. We know that Earth's mass was formed by accretion. Over time, many many years, the material started to be organised by densities thanks to gravity. The Earth's core is mainly made out of iron because iron is denser than silicate materials which are the most common on the Earth's crust.