Question

Which one of the following represents the correct electronic orbital configuration of Phosphorus (+3) ion ($P^{3+}$)?

• A. $1s^2 2s^2 2p^6 3s^2$
• B. $1s^2 2s^2 2p^6 3s^1$
• C. $1s^2 2s^2 2p^4 3s^2$
• D. $1s^2 2s^2 2p^5 3s^1$

Hint:

Always remove electrons from the highest energy level ($p$ before $s$) when forming cations.

Answer 1

The Correct Option is A

Step 1: Concept
Phosphorus ($P$) has an atomic number of 15. Its neutral configuration is $1s^2 2s^2 2p^6 3s^2 3p^3$.

Step 2: Meaning
A $P^{3+}$ ion is formed by removing three electrons from the outermost shell.

Step 3: Analysis
The electrons are removed from the $3p$ orbital first. Removing 3 electrons from $3p^3$ leaves it empty.

Step 4: Conclusion
The resulting configuration is $1s^2 2s^2 2p^6 3s^2$. Final Answer: (A)