How many neutrons are in an atom of iridium-192?

Iridium-192 has an atomic number of 77, which means it has 77 protons. The Atomic Mass of iridium-192 is approximately 192 atomic mass units (amu). To find the number of neutrons, subtract the number of protons from the atomic mass: 192 - 77 = 115. Therefore, an atom of iridium-192 contains 115 neutrons.