Ans: In carbonyl compounds, the carbon-oxygen bond is polar. Oxygen is more electronegative than carbon. It pulls the shared pair of electrons towards itself and develops a slight negative charge over itself; this results in a slight positive charge over the carbonyl carbon atom. This carbon atom acts as an electrophile and accounts for the nucleophilic addition reaction of carbonyl compounds. In ketones, the positive charge of the carbonyl carbon is stabilised by the adjacent alkyl groups.