Answer: A. The atomic number is 31, the mass number is 67, and its symbol is

Step-by-step explanation:
Atomic number is defined as the number of protons or number of electrons that are present in an electrically neutral atom.
Atomic number = Number of protons = 31
Mass number is defined as the sum of number of protons and neutrons that are present in an atom.
Mass number = Number of protons + Number of neutrons = 31 + 36 = 67
The isotopic representation of a radionuclide is:
where,
Z = Atomic number of the atom
A = Mass number of the atom
X = Symbol of the atom
Thus the atom is written as
