Question: 1 br2 molecule has a mass of amu?
Answer: (iii) The element bromine consists of diatomic molecules and so it is represented by the molecular formula, Br2 and not by the symbol for its atom, Br. The atomic weight of bromine is 79.90 so its molecular weight = 2 × 79.90 = 159.8 or its molar mass = 159.8 g mol–1.