Chemistry S & P Block Elements BUMHS 2023
PMDC Verified Question 44 of 104
The general electronic configuration of halide ions is
A
\( ns^2 np^5 \)
B
\( ns^2 np^6 \)
C
\( ns^1 np^5 \)
D
\( ns^2 np^3 \)
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option B: \( ns^2 np^6 \)
Concept:

Halogens (Group 17) naturally have 7 valence electrons. To become stable ions, they complete their octet.

Solution:

  • Neutral halogens (like Fluorine, Chlorine, etc.) have the general valence configuration of \( ns^2 np^5 \).
  • To achieve maximum stability, a halogen atom gains one electron to form a halide anion (e.g., \( \text{F}^-, \text{Cl}^- \)).
  • This extra electron enters the p-orbital, completing the octet.
  • The new configuration becomes \( ns^2 np^6 \), which is the incredibly stable, full-shell configuration of a noble gas.


Why other options are incorrect:

  • \( ns^2 np^5 \): This is the configuration of the neutral halogen atom, not the ion.
  • Options C & D: Incorrect orbital filling patterns for Group 17.

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