To determine the number of protons, neutrons, and electrons in the ion \( S^{2-} \) with an atomic number of 16 and a mass number of 33, follow these steps:
1. Identify the atomic number and mass number:
- The atomic number (\( Z \)) of sulfur (S) is 16. This means sulfur has 16 protons.
- The mass number (\( A \)) given in the notation \( \frac{33}{16} S \) is 33.
2. Determine the number of neutrons:
- The number of neutrons (\( n \)) is calculated by subtracting the atomic number from the mass number:
[tex]\[
n = A - Z = 33 - 16 = 17
\][/tex]
- Thus, there are 17 neutrons.
3. Determine the number of electrons for the neutral atom:
- In a neutral atom, the number of electrons is equal to the number of protons. Therefore, a neutral sulfur atom (\( S \)) has 16 electrons.
4. Adjust for the ion charge:
- The given ion is \( S^{2-} \), which indicates it has a 2- charge. This means the ion has gained 2 additional electrons compared to the neutral atom.
- Therefore, the number of electrons in \( S^{2-} \) is:
[tex]\[
\text{Electrons} = 16 + 2 = 18
\][/tex]
Given this information, the \( S^{2-} \) ion has:
- 16 protons
- 17 neutrons
- 18 electrons
Thus, the correct answer is:
[tex]\[
\boxed{16 p^{+}, 17 n^{\circ}, 18 e^{-}}
\][/tex]
