Answer to Question #217632 in General Chemistry for Locked

Question

From your knowledge of geochemistry, which of the six (6) elements Si, Mg, Al, Fe, K and Ca would you expect to be enriched in

a. the earth's crust

b. the earth's mantle

       Give reasons for your answer.

Answer 1

a) Si

The mass-abundance of the nine most abundant elements in the Earth's crust is approximately: oxygen 46%, silicon 28%, aluminum 8.3%, iron 5.6%, calcium 4.2%, sodium 2.5%, magnesium 2.4%, potassium 2.0%, and titanium 0.61%. Other elements occur at less than 0.15%

b)Si

Common silicates found in the mantle include olivine, garnet, and pyroxene. The other major type of rock found in the mantle is magnesium oxide. Other mantle elements include iron, aluminum, calcium, sodium, and potassium.