Answer
Following is the symbol for the isotope of bismuth:
Work Step by Step
Bismuth has the chemical symbol 'Bi'.
Bi has 83 protons. That means Atomic Number = 83. (Atomic number = no. of protons)
This isotope contains 124 neutrons.
Hence, Mass number = 83+124 = 207. (Mass number = no. of protons + no. of neutrons)
Hence, the symbol of the isotope can be written by writing the chemical symbol and providing the atomic number on left subscript and mass number on left superscript as mentioned below: