How many protons and neutrons are in the Platinum - 195 isotope, ¹⁹⁵Pt?

Question

Quizplus · Accepted Answer

The isotope symbol ¹⁹⁵Pt indicates that the atomic number (number of protons) is 78 (the "Pt" stands for platinum and has an atomic number of 78). The mass number (number of protons and neutrons) is 195, so subtracting the atomic number from the mass number gives the number of neutrons: 195 - 78 = 117. Therefore, the answer is D) 78 protons, 117 neutrons.

How Many Protons and Neutrons Are in the Platinum -