Question

An atom of gold with 79 protons, 79 electrons, and 118 neutrons would have a mass number of
Responses

39
39

158
158

197
197

276
276

Answers

GPT-4o mini
The mass number of an atom is the sum of the number of protons and neutrons in its nucleus. For an atom of gold with 79 protons and 118 neutrons, the mass number can be calculated as follows:

\[
\text{Mass number} = \text{Number of protons} + \text{Number of neutrons}
\]
\[
\text{Mass number} = 79 + 118 = 197
\]

Thus, the mass number of the atom of gold you described is **197**.