An isoelectronic pair among the following is:

(a) Na⁺, Mg²⁺ 

(b) Al³⁺, O^– 

(c) Na⁺, O^2– 

(d) N^3-, Cl^– 

CO is isoelectronic with

(a) ${\mathrm{NO}}^{+}$

(b) ${\mathrm{N}}_2$

(c) ${\mathrm{SnCl}}_2$

(d) ${\mathrm{NO}}_2^{-}$

Choose the correct option

1. (a), (b)

2. (b), (c)

3. (c), (d)

4. (b), (d)

Among the options given below, identify the Isoelectronic species:

1. CO, CN^–, NO⁺, C₂^2–

2. CO^–, CN, NO, C₂^–

3. CO⁺, CN⁺, NO^–, C₂

4. CO, CN, NO, C₂

Among the following, the group constitutes only isoelectronic species is:

1. ${\mathrm{NO}}^{+},<mspace\; width="1em"></mspace>{\mathrm{C}}_2^{2-},<mspace\; width="1em"></mspace>{\mathrm{CN}}^{-},<mspace\; width="1em"></mspace>{\mathrm{N}}_2$

2. ${\mathrm{CN}}^{-},<mspace\; width="1em"></mspace>{\mathrm{N}}_2,<mspace\; width="1em"></mspace>{\mathrm{O}}_2^{2-},<mspace\; width="1em"></mspace>{\mathrm{C}}_2^{2-}$

3. ${\mathrm{N}}_2,<mspace\; width="1em"></mspace>{\mathrm{O}}_2^{-}.<mspace\; width="1em"></mspace>{\mathrm{NO}}^{+},<mspace\; width="1em"></mspace>\mathrm{CO}$

4. ${\mathrm{C}}_2^{2-},<mspace\; width="1em"></mspace>{\mathrm{O}}_2^{-},<mspace\; width="1em"></mspace>\mathrm{CO},<mspace\; width="1em"></mspace>\mathrm{NO}<mspace\; width="1em"></mspace>$

Which of the following attain the linear structure?

(a) ${\mathrm{BeCl}}_2$

(b) ${\mathrm{NCO}}^{+}$

(c) ${\mathrm{NO}}_2$

(d) ${\mathrm{CS}}_2$

Choose the correct option

A molecule, among the following, that obeys the octet rule is:

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. $PC{l}_5$ $,$ $IC{I}_5$