The electron configuration of the P3- ion is 1s2 2s2 2p6 3s2 1s2 2s2 2p6 3d2 3p6 none of the answers are correct 1s2 2s2 2p6 3d5 3p3
The Correct Answer and Explanation is:
The correct electron configuration of the P³⁻ ion is:
1s² 2s² 2p⁶ 3s² 3p⁶
Here’s why:
Phosphorus (P) has an atomic number of 15, meaning its neutral atom has 15 electrons. The electron configuration for neutral phosphorus is:
1s² 2s² 2p⁶ 3s² 3p³
This means it has 2 electrons in the first shell (1s²), 2 electrons in the second shell (2s²), 6 electrons in the second shell’s p orbitals (2p⁶), 2 electrons in the third shell’s s orbital (3s²), and 3 electrons in the third shell’s p orbital (3p³).
When phosphorus forms a P³⁻ ion, it gains three additional electrons to fill its outermost 3p orbital. The added electrons go into the 3p orbital, completing it, which now contains 6 electrons in total. So, the electron configuration of the P³⁻ ion is:
1s² 2s² 2p⁶ 3s² 3p⁶
This configuration matches the electron configuration of the noble gas Argon (Ar), which is the stable configuration for the P³⁻ ion.
Regarding the other options:
- The configuration 1s² 2s² 2p⁶ 3s² 3d² 3p⁶ suggests that phosphorus has electrons in the 3d orbital, which is incorrect for the P³⁻ ion.
- 1s² 2s² 2p⁶ 3d⁵ 3p³ also doesn’t reflect the correct configuration, as it suggests an odd number of electrons in the 3d orbital and violates the rules for how electrons fill orbitals (3d orbitals are typically filled after 4s, and they don’t come into play until higher atomic numbers).
Thus, the correct configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ for the P³⁻ ion.
