In the following questions two or more options may be correct.

CO is isoelectronic with

A. NO⁺

B. N₂

C. SnCl₂

D. NO₂

Isoelectronic species are the atoms of different elements with the same number of electrons.

Both (i), (ii) have 14 electrons and CO also has 14 electrons (6 electrons of C and 8 electrons of Oxygen).

SnCl₂ has 84 electrons (50 electrons of Sn and 34 electrons of Cl₂ ) and NO₂ has 23 electrons (7 electrons of N and 16 electrons of O₂).