Question

(i) What is a lone pair of electrons?
(ii) Draw an electron dot diagram of a hydronium ion and label the lone pair of electrons.
(iii) Name a neutral covalent molecule which contains one lone pair of electrons.

Answer 1

(i) The pair of valence electrons on an atom in a molecule that does not participate in covalent bonding with another atom is known as the lone pair of electrons.

(ii) Electron dot structure of hydronium ion:
$$\begin{gathered} {\left[H:\underset{\mathbf{.}\mathbf{.}}{\overset{\underset{..}{H}}{O}}:H\right]}^{+} \\ \downarrow \\ Lonepair \end{gathered}$$

(iii) Ammonia (NH₃) is a neutral covalent molecule that contains one lone pair of electrons on a nitrogen atom.