Question

Bromine is the only nonmetal that is a liquid at room temperature. consider the isotope bromine-81, . select the combination which lists the correct atomic number, number of neutrons, and mass number, respectively.

Answer 1

Answer:
atomic number=35
number of neutrons=46
mass number=81


The number that written on isotopes is showing the mass number of the molecule, so Bromine-81 mass number is 81. The atomic number of bromine(look at the periodic table) should be 35 which means it has 35 protons. The number of neutron should be: mass-proton= 81-35= 46.