how many protons neutrons and electrons are there in an atom of gold-197?
The susbcript 197 is the mass number the sum of the numbers of protons and neutrons. According to the list of elements given in the perioidc table gold has atomic number 79. Consequently, and 197 Au atom has 79 protons,79 electrons and 197-79 = 118 neutrons. 79 protons,79 electrons and 118 neutrons.