Which equation is balanced? a.) K + MgBr ---> KBr + Mg b.) HNO3 + NaHCO3 ---> NaNO3 + H2O + CO2 c.) 6H2O + 3O2 ---> 6H2O2

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.

well the answer is 2!

multiply it by 5 in order for you to understand i cant give an exact answer.

answer; civil inattention;