SOMEONE HELP QUICK PLS

what are ways significant digits can be used in the real world

If 16.00g of hydrogen gas reacts with 126.73g of oxygen, how many grams of water are yielded? (both reactants are completely consumed in the reaction.)

Which substance—wood or silver—is the better thermal conductor? a thermal conductor is a material that requires very little heat energy to change its temperature. explain your answer.

What are the coefficients that will balance the skeleton equation below? n2 + h2 → nh3