When the earth was formed and cooled, why did nickel and iron end up in the center of the earth while basalt and granite ended up in the outer layers

Iwill give extra points to who gets this right

Acompound contains c, h, and o atoms. when 1.130 g of the compound is burned in oxygen, 1.064 g co2 and 0.3631 g h2o are produced. what is the empirical formula of this compound?

Write a balanced equation showing the formation of copper (ii) nitrite from its elements