Symbols 79 35Br and 79Br can be written, whereas symbols 35 79Br and 35Br are not acceptable. Answer briefly.

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⁷⁹ ₃₅Br and 79Br are acceptable way of representation whereas 35 79Br and 35Br are not acceptable because there is a rule in IUPAC nomenclature to write the higher number(mass number) on top and the lower number (atomic number ) at the bottom. This type of expressing the elements is very useful in writing radioactive disintegration reactions where neutrons are emitted.