The Composition of Gold Ion 197/79Au³⁻

What is the composition of the gold ion 197/79Au³⁻?

a) Protons: 79, Neutrons: 118, Electrons: 76
b) Protons: 79, Neutrons: 118, Electrons: 79
c) Protons: 79, Neutrons: 118, Electrons: 76
d) Protons: 79, Neutrons: 118, Electrons: 118

Answer:

The gold ion 197/79Au³⁻ has 79 protons, 118 neutrons, and 82 electrons.

The ion 197/79Au³⁻ represents the gold ion with a charge of -3. To determine the number of protons, neutrons, and electrons, we look at the atomic number and mass number of gold. The atomic number of gold is 79, which tells us that it has 79 protons. The mass number of gold is 197, which is the sum of protons and neutrons. Subtracting the number of protons from the mass number, we can find the number of neutrons: 197 - 79 = 118 neutrons. Since the gold ion has a charge of -3, it means that there are 3 more electrons than protons. Therefore, the number of electrons in the gold ion is: 79 + 3 = 82 electrons.