The total mass of the protons in an atom of gold-198 is approximately
(1) 79 atomic mass units
(2) 119 atomic mass units
(3) 198 atomic mass units
(4) 277 atomic mass units



Answer :

Gold has an atomic number of 79
Protons have a relative mass of 1
Gold-198 is a radioactive isotope of gold, which means it has a different number of neutrons, but the same number of protons and electrons
So the answer is (1) 79 atomic mass units