The lone pairs of electrons can be defined as -

1. Electron pairs that participate in bonding.

2. Electron pairs  that do not participate in bonding.

3. Electron pairs that are present in inner most shell.

4.Electron pairs that are present in valence shell of ions.

The correct Lewis structure of acetic acid is:
 

1.		2.
3.		4.	None of the above.

An electron-deficient compound among the following is:

The Lewis dot symbols for atoms of the elements Mg, Na, O, and N, respectively, would be:

1.
2.
3.
4.

Lewis symbols for the atoms and ions: S and S^2–; Al and Al³⁺; H and H^– respectively, would be:

1.		${\left[\mathbf{:}\underset{\mathbf{.}\mathbf{.}}{\overset{\mathbf{.}\mathbf{.}}{\mathrm{S}}}\mathbf{:}\right]}^{2-}$	${\left[\mathrm{Al}\right]}^{3+}$
2.		${\left[\mathbf{:}\underset{\mathbf{.}\mathbf{.}}{\overset{\mathbf{.}\mathbf{.}}{\mathrm{S}}}\mathbf{:}\right]}^{2-}$		${\left[\mathrm{Al}\right]}^{3+}$
3.	${\left[\mathbf{:}\underset{\mathbf{.}\mathbf{.}}{\overset{\mathbf{.}\mathbf{.}}{\mathrm{S}}}\mathbf{:}\right]}^{2-}$			${\left[\mathrm{Al}\right]}^{3+}$
4.		${\left[\mathbf{:}\underset{\mathbf{.}\mathbf{.}}{\overset{\mathbf{.}\mathbf{.}}{\mathrm{S}}}\mathbf{:}\right]}^{2-}$		${\left[\mathrm{Al}\right]}^{3+}$

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

1. $\mathrm{S}{{\mathrm{O}}_3}^{-2}, {\mathrm{CO}}_3^{2-}, \mathrm{N}{{\mathrm{O}}_3}^{-}$

2. ${\mathrm{CN}}^{-}, {\mathrm{N}}_2, \mathrm{CO}$

3. ${\mathrm{BO}}_3^{3-} , {\mathrm{CO}}_3^{2- },\mathrm{N}{{\mathrm{O}}_3}^{-}$

4. ${\mathrm{PO}}_4^{3-}, {\mathrm{SO}}_4^{2-}, \mathrm{Cl}{{\mathrm{O}}_4}^{-}$

Identify the wrong statement among the following: 

1. Amongst isoelectronic species, the smaller the positive charge on the cation, the smaller the ionic radius.
2. Amongst isoelectronic species, the greater the negative charge on the anion, the larger is the ionic radius.
3. The atomic radius of the elements increases as one moves down the first group of the Periodic Table.
4. The atomic radius of the elements decreases as one moves across from left to right in the 2nd period of the Periodic Table.

Which of the following pairs of ions are isoelectronic and isostructural?

1. ${\mathrm{CO}}_3^{2-}, {\mathrm{SO}}_3^{2-}$

2. ${\mathrm{ClO}}_3^{-}, {\mathrm{CO}}_3^{2-}$

3. ${\mathrm{SO}}_3^{2-}, {\mathrm{NO}}_3^{-}$

4. ${\mathrm{ClO}}_3^{-}, {\mathrm{SO}}_3^{2-}$

The significance of the octet rule is:

1. To determine the stability of atoms.

2. To find the hybridization of elements.

3. To calculate the number of lone pairs.

4. None of the above.

From the following pairs of ions which one is not an iso-electronic pair?

1. Mn²⁺, Fe³⁺

2. Fe²⁺, Mn²⁺

3. O^2-, F^-

4. Na⁺, Mg²⁺