Number of atoms in water

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

How many liters of water vapor can be produced if 108 grams of methane gas (ch4) are combusted at 312 k and 0.98 atm? show all work. pls ! will mark as brainliest

In an exothermic reaction the bonding energy of the product is: less than the reactants same as the reactants greater than the reactants dependent upon the presence of a catalyst