Which of the following is isoelectronic?

Question

Question

This question was previously asked in

AIIMS BSc NURSING 2023 Memory-Based Paper

Answer 1

CONCEPT:

Isoelectronic Species

Isoelectronic species are atoms, ions, or molecules that have the same number of electrons.
To determine if species are isoelectronic, count the total number of electrons in each species and compare them.

EXPLANATION:

Calculate the number of electrons in each species:
- CO₂: C (6 electrons) + 2 * O (8 electrons each) = 6 + 16 = 22 electrons
- NO₂: N (7 electrons) + 2 * O (8 electrons each) = 7 + 16 = 23 electrons
- NO₂^-: N (7 electrons) + 2 * O (8 electrons each) + 1 extra electron = 7 + 16 + 1 = 24 electrons
- CN^-: C (6 electrons) + N (7 electrons) + 1 extra electron = 6 + 7 + 1 = 14 electrons
- CO: C (6 electrons) + O (8 electrons) = 6 + 8 = 14 electrons
- SO₂: S (16 electrons) + 2 * O (8 electrons each) = 16 + 16 = 32 electrons
Identify the isoelectronic pairs:
- CN^- (14 electrons) and CO (14 electrons) are isoelectronic.

Therefore, the correct answer is Option 3: CN^- and CO.