Answer :
Final answer:
An atom of gold-195 has 79 protons, 116 neutrons, and 79 electrons (option A).
Explanation:
An atom of gold-195 has 79 protons, 116 neutrons, and 79 electrons. The atomic number of an element represents the number of protons in its nucleus. Since gold-195 is an isotope of gold, it has the same number of protons as the element gold, which is 79. Additionally, the mass number of an isotope is the sum of its protons and neutrons.
Therefore, the number of neutrons in gold-195 can be calculated by subtracting the atomic number (protons) from the mass number. In this case, it would be 195 - 79 = 116 neutrons. The number of electrons in a neutral atom is equal to the number of protons. So, gold-195 has 79 electrons.
