Both aldehydes & ketones contain carbonyl group as their functional group.
Both aldehydes & ketones have carbonyl group as the functional group. The carbonyl carbon is sp2 hybridised & it uses sp2 hybrid orbitals to form 3σ bonds, one with oxygen atom & remaining 2 with two other atoms or groups (R or H). All these 3σ bonds lie in same plane at the angle of 120°.
The unhybridized p – orbital of carbonyl carbon form π - bond with oxygen atom by sidewise overlapping with half filled
Since carbon & oxygen have different values of electronegativity, the bond between carbon & oxygen is polar. Infact electron density around the oxygen atom is increased which causes the development of partial positive charge (δ+) on carbon & δ− on oxygen.
Thus the carbonyl carbon is an electrophilic & carbonyl oxygen is nucleophilic centre.
Orbital picture of carbonyl group