Molecule/Ion that is diamagnetic in nature is: 

1.	\(\mathrm{H}^-_2\)	2.	\(\mathrm{H}_2\)
3.	\(\mathrm{H}^+_2\)	4.	\(\mathrm{He}^+_2\)

The extent of lattice energy in an ionic compound depends on:

1. Packing of ions only 

2. Size of the ions only 

3. Charge and Size of the ions 

4. Charge on the ions only

The number and type of bonds between two carbon atoms in calcium carbide are 

1. One sigma, two pi

2. Two sigma, two pi 

3. One sigma, one pi 

4. Two sigma, one pi 

Which among the following does not contain a set of isoelectronic species?

1. $\mathrm{S}{{\mathrm{O}}_3}^{2-\mathrm{}}$, CO₃^2-,NO₃^-

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

3. ${\mathrm{BO}}_3^{3-}<mspace\; width="1em"></mspace>,<mspace\; width="1em"></mspace>{\mathrm{CO}}_3^{2-<mspace\; width="1em"></mspace>},\mathrm{N}{{\mathrm{O}}_3}^{-}$

4. ${\mathrm{PO}}_4^{3-},<mspace\; width="1em"></mspace>{\mathrm{SO}}_4^{2-},<mspace\; width="1em"></mspace>\mathrm{Cl}{{\mathrm{O}}_4}^{-}$

Which of the following molecules/ions does not contain unpaired electrons?

(1) O${}_2^{<mspace\; width="1em"></mspace>2-}$

(2) ${{\mathrm{C}}_2}^{-}$

(3) $N_2^{+}$

(4) O${}_2$

A molecule or ion that has an unequal bond length is:

Which of the following species exhibits the diamagnetic behaviour?

(1) O${}_2^{<mspace\; width="1em"></mspace>+}$

(2) O${}_2$

(3) NO

(4) O${}_2^{<mspace\; width="1em"></mspace>2-}$

The correct increasing order of the polarizing power of the cationic species  ${\mathrm{K}}^{+},<mspace\; width="1em"></mspace>{\mathrm{Ca}}^{2+},<mspace\; width="1em"></mspace>{\mathrm{Mg}}^{2+},<mspace\; width="1em"></mspace>{\mathrm{Be}}^{2+}$is: 

1. ${\mathrm{Be}}^{2+}<{\mathrm{K}}^{+}<{\mathrm{Ca}}^{2+}<{\mathrm{Mg}}^{2+}$

2. ${\mathrm{K}}^{+}<{\mathrm{Ca}}^{2+}<{\mathrm{Mg}}^{2+}<{\mathrm{Be}}^{2+}$

3. ${\mathrm{Ca}}^{2+}<{\mathrm{Mg}}^{2+}<{\mathrm{Be}}^{2+}<{\mathrm{K}}^{+}$

4. ${\mathrm{Mg}}^{2+}<{\mathrm{Be}}^{2+}<{\mathrm{K}}^{+}<{\mathrm{Ca}}^{2+}$

Which one of the following pair of species have the same bond order?

(1) CN${}^{-}$ and NO${}^{+}$

(2) CN and CN${}^{+}$

(3) O${}_2^{<mspace\; width="1em"></mspace>-}$ and CN${}^{-}$ 

(4) NO${}^{+}$ and CN${}^{+}$

Among the following, the maximum covalent character is shown by which compound:

1. ${\mathrm{MgCl}}_2$

2.$$ ${\mathrm{FeCl}}_2$

3. ${\mathrm{AlCl}}_3$

4. ${\mathrm{SnCl}}_2$