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

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 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.

The correct Lewis structure of acetic acid is:
 

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