Explain the reactivity of nucleophilic addition reactions of aldehyde and ketone compounds.

(N/A) Aldehydes are generally more reactive than ketones in nucleophilic addition reactions due to steric and electronic factors.
$(i)$ Steric effect: Sterically,the presence of two relatively large substituents in ketones hinders the approach of the nucleophile to the carbonyl carbon more than in aldehydes,which have only one such substituent.
$(ii)$ Electronic effect: Electronically,aldehydes are more reactive than ketones because two alkyl groups in ketones reduce the electrophilicity of the carbonyl carbon more effectively than the single alkyl group in aldehydes.
In an aldehyde $(RCHO)$,only one $-R$ group is present,while in a ketone $(RCOR)$,two alkyl groups are present,which reduces the electrophilicity of the carbonyl group.