Elemental iridium is composed of two stable isotopes, iridium-191 and iridium-193. (a) How many protons and neutrons are found in these two isotopes of iridium? Iridium-191 has has protons and protons and (b) The isotopic notation for iridium-191 is Ir, where A is The isotopic notation for iridium-193 is Ir, where A is 193 neutrons. neutrons, iridium-193 and Z is and Z is (c) Calculate the mass percent of protons in the nucleus of each of these isotopes. % of protons in Iris % of protons in Ir is i