Due in 5 min PLEAZE HELP!!

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

7. what temperature is need to just dissolve 50 g of nh4cl in 75 g of water? '

Given sno2 + 2h2 - sn + 2h20 tin oxide reacts with hydrogen to produce tin and water. how many moles of sno2 are needed to produce 500.0 grams of sn?