Consider an atom of gold in which the nucleus contains 79 protons and 118 neutrons. What is its atomic number and atomic mass number?
A)The atomic number is 118, and the atomic mass number is 79.
B)The atomic number is 79, and the atomic mass number is 197.
C)The atomic number is 79, and the atomic mass number is 118.
D)The atomic number is 118, and the atomic mass number is 197.

Question

Quizplus · Accepted Answer

The atomic number is equal to the number of protons in the nucleus, which is 79 in this case. The atomic mass number is equal to the sum of the number of protons and neutrons in the nucleus, which is 79 + 118 = 197. Therefore, option B is correct. Option A is incorrect because the atomic number cannot be greater than the atomic mass number. Option C is also incorrect because the atomic mass number cannot be equal to the number of protons or neutrons alone. Option D is incorrect because the atomic number cannot be greater than the atomic mass number.

Consider an Atom of Gold in Which the Nucleus Contains