Which of the two species, NO₃⁻ or H₃O⁺, has the correctly described properties listed below?

1.	Isostructural with the same hybridization for the central atom.
2.	Isostructural with different hybridization for the central atom.
3.	Similar in hybridization for the central atom with different structures.
4.	Dissimilar in hybridization for the central atom with different structures.

The most preferred structure among the following with the lowest energy for SO₃ is: 

1.		2.
3.		4.

The pairs of species of oxygen and their magnetic behaviours are given below. Which of the following represents the correct description?

1. $\mathrm{O},$ ${\mathrm{O}}_2^{2-}$ - Both paramagnetic
2. ${\mathrm{O}}_2^{-},$ ${\mathrm{O}}_2^{2-}$ - Both diamagnetic
3. ${\mathrm{O}}^{+},$ ${\mathrm{O}}_2^{2-}$ - Both paramagnetic
4. ${\mathrm{O}}_2^{+},$ ${\mathrm{O}}_2$ - Both paramagnetic

Four diatomic species are listed below. Identify the correct order in which the bond order is increasing in them.
1. O₂^– < NO < C₂^2– < He₂⁺  
2. C₂^2– < He₂⁺ < O₂^– < NO  
3. He₂⁺ < O₂^– < NO < C₂^2–
4. NO < O₂^– < C₂^2– < He₂⁺  

Which orbital does the additional electron occupy when O₂ is converted to the O₂⁻ ion?

1. $\pi$ $\mathrm{orbital}$ $$

2. $\sigma *$ $\mathrm{orbital}$ $$

3. $\sigma$ $\mathrm{orbital}$

4. $\pi *$ $\mathrm{orbital}$ $$

Among the following, the compound that is electron deficient is:

1. BaCl₂

2. BCl₃

3. CCl₄

4. PCl₅

d$\mathrm{\pi }$ - p$\mathrm{\pi }$ bond is present in:

1. $C{O}_3^{2-}$

2. $P{O}_4^{-3}$

3. $N{O}_3^{-}$

4. $N{O}_2^{-}$

The compound that forms linear polymer due to H-bond is:

The correct order of dissociation energy of N₂ and N₂⁺ is:

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