Which pair of ions among the following list do not constitute an iso-electronic pair?

1. Mn²⁺, Fe³⁺

2. Fe²⁺, Mn²⁺

3. O^2–, F^–

4. Na⁺, Mg²⁺

Identify the incorrect statement among the following:

Among the following, iso-electronic species are:

1. CO₂, NO₂

2. $N{O}_2^{-}$, CO₂

3. CN^–, CO

4. SO₂, CO₂

Which of the following two species in the pair are isostructural:

1.  $Xe{F}_2$ $,$ $I{F}_2^{-}$

2. $N{H}_3$ $,$ $B{F}_3$

3. $$ $C{O}_3^{-2}$ $,$ $S{O}_3^{-2}$

4. $PC{l}_5$ $,$ $IC{l}_5$

Which of the following compounds is electron deficient?

1. BaCl₂

2. BCl₃

3. CCl₄

4. PCl₅

Which of the following sets consists of isoelectronic species?

1. CO, CN^–, NO⁺, C₂^2–

2. CO^–, CN, NO, C₂^–

3. CO⁺, CN⁺, NO^–, C₂

4. CO, CN, NO, C₂