The lone pairs of electrons can be defined as:

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.
2.
3.
4.

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

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

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

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

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

Which of the following statements is incorrect?

1. Amongst isoelectronic species, smaller the positive charge on the cation, smaller the ionic radius.
2. Amongst isoelectronic species, greater the negative charge on the anion, larger 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.

Which pair of ions from the following list do not constitute an iso-electronic pair?

1. Mn²⁺, Fe³⁺

2. Fe²⁺, Mn²⁺

3. O^2–, F^–

4. Na⁺, Mg²⁺