To determine the number of protons, neutrons, and electrons in an S2- ion, we need to start with the basic information about sulfur (S).
1. **Protons:** The atomic number of sulfur is 16, which means a neutral sulfur atom has 16 protons. Therefore, an S2- ion also has 16 protons.
2. **Electrons:** The S2- ion indicates that the sulfur atom has gained 2 extra electrons. In a neutral atom, the number of electrons equals the number of protons. So, the S2- ion has:
- 16 (protons) + 2 (extra electrons) = 18 electrons
3. **Neutrons:** The number of neutrons can be found using the atomic mass of sulfur, which is approximately 32 atomic mass units. To find the neutrons, we can use the formula:
- Neutrons = Atomic Mass – Protons
Calculating this gives us:
- 32 (approximate atomic mass) – 16 (protons) = 16 neutrons
Putting it all together, an S2- ion has:
- Protons: 16
- Neutrons: 16
- Electrons: 18