\({\%~of~an~element} = \frac{mass~of~an~element~in~the~compound}{relative~formula~mass~M_r} \times 100\) There are six atoms of hydrogen in the compound, so the mass ...

Part of Combined Science Structures, trends, chemical reactions, quantitative chemistry and analysis 25% of chlorine atoms are 37 Cl and 75% are 35 Cl. The weighted mean mass of chlorine is 35.5. The ...