Which agent of erosion is probably at work in the area

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

Which orbitals form a pi bond? a.the s orbital and three p orbitals b.the s orbital and two p orbitals c.overlapping p orbitals d.overlapping hybrid orbitals

What is the correct equation for cellular respiration?