Generally the percentage of an atom in a compound is measured by the percentage of its mass in the compound. So, Mass of oxygen = 16 amu Mass of hydrogen = 1 amu Mass of water(H2O)=(2×1+16) amu = 18amu % of oxygen in water=(16/18)×100%=88. read more
Dissolved Oxygen in Water. Although the rate of depletion is a better metric. biological oxygen demand (BOD) Standard method for indirect measurement of the amount of organic pollution (that can be oxidized biologically) in a sample of water. read more