How many protons are found in the nucleus of one atom of gold?

Hint For calculating the number of protons in an atom we have to know about the atomic number of that atom, because Atomic number (${\text{Z}}$) of an atom is always equal to the number of protons present inside the nucleus or number of electrons present outside the nucleus in the orbitals.

Complete step by step solution: Gold is situated in the 5d series of the d – block in the periodic table and denoted by the symbol as ${}_{{\text{197}}}^{{\text{79}}}{\text{Au}}$.
-Upper quantity in ${}_{{\text{197}}}^{{\text{79}}}{\text{Au}}$ describes the atomic number (${\text{Z}}$) of the gold atom.
-Lower quantity in ${}_{{\text{197}}}^{{\text{79}}}{\text{Au}}$ describes the atomic mass (${\text{A}}$) of the gold atom.
-As we know that relation between the atomic number and number of protons present inside the nucleus is represented as follow:
Atomic Number (${\text{Z}}$) = No. of protons = No. of electrons
-From the denotation of gold it is clear that the atomic number of gold is $79$, so the number of protons in the gold atom is also $79$.
Hence, in the nucleus of one atom of gold $79$ protons are found.

Additional information:
Number of protons present inside the nucleus in an atom is also calculated by knowing the atomic mass (${\text{A}}$) and number of neutrons as follow:
Atomic mass (${\text{A}}$) = No. of protons + No. of neutrons.

Note: Here some of you may get confused on calculating the number of protons if atomic mass (${\text{A}}$) and atomic number (${\text{Z}}$) both are given, then in this condition always keep in mind that atomic number is equal to number of protons.