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

Which of the following molecules has trigonal planar geometry:

Which of the following would have a permanent dipole moment:

1. BF₃

2. SF₄

3. SiF₄

4. XeF₄

The correct sequence of increasing covalent character is represented by:

1. ${\mathrm{BeCl}}_2<\mathrm{NaCl}<\mathrm{LiCl}$

2. $\mathrm{NaCl}<\mathrm{LiCl}<{\mathrm{BeCl}}_2$

3. ${\mathrm{BeCl}}_2<\mathrm{LiCl}<\mathrm{NaCl}$

4. $\mathrm{LiCl}<\mathrm{NaCl}<{\mathrm{BeCl}}_2$

Which of the following is the electron deficient molecule:

1. C₂H₆ 

2. SiH₄

3. PH₃

4. B₂H₆ 

A species that does not exhibit paramagnetism is:

1. N₂⁺

2. O₂^–

3. CO

4. NO

In $P{O}_4^{-3}$, formal charge on every oxygen atom and P-O bond order respectively are:
1.  -0.75 and 1.25
2.  -0.5 and 2
3.  1 and 1.5
4.  -0.75 and 2

Among the following, the pair in which the two species are not isostructural is:

1. ${\mathrm{IO}}_3^{-}\text{and }{\mathrm{XeO}}_3$

2. ${\mathrm{BH}}_4^{-}\text{and }{\mathrm{NH}}_4^{+}$

3. ${\mathrm{PF}}_6^{-}\text{and }{\mathrm{SF}}_6$

4. ${\mathrm{SiF}}_4\text{ and }{\mathrm{SF}}_4$

Increasing order of bond length is:

1. $N{O}^{-}$ $<$ $NO$ $<$ $N{O}^{+}$ $<$ $O_2^{-}$

2. $O_2^{-}$ $<$ $NO$ $<$ $N{O}^{-}$ $<$ $N{O}^{+}$ $$

3. $O_2^{-}$ $<$ $N{O}^{-}$ $<$ $NO<$ $N{O}^{+}$ $$

4. $N{O}^{+}$ $<$ $NO$ $<$ $N{O}^{-}$ $<$ $O_2^{-}$

H₂O is dipolar, whereas BeF₂ is not. It is because: