The correct answer is a) 92 protons, 92 electrons, and 146 neutrons. Let’s break this down:
Uranium-238 is one of the most common isotopes of uranium. The number in its name, 238, refers to the total number of protons and neutrons in its nucleus. The atomic number of uranium is 92, which means there are 92 protons in the nucleus. Since the number of electrons in a neutral atom is equal to the number of protons, uranium-238 also has 92 electrons.
To find the number of neutrons, we subtract the number of protons from the mass number: 238 (mass number) – 92 (protons) = 146 neutrons. Therefore, the composition of uranium-238 is as follows:
- Protons: 92
- Electrons: 92
- Neutrons: 146
Thus, uranium-238 has 92 protons, 92 electrons, and 146 neutrons, making option a) the correct choice.