Why do aldehydes and ketones undergo nucleophilic addition reactions. Give one example.

Why do aldehydes and ketones undergo a number of addition reactions ?

A : Aldehydes and ketones undergo nucleophilic addition reaction. R : Aldehydes and ketones contain carbonyl group.

Which gives nucleophilic addition reaction?

What are nucleophilic substitution reactions ? Give an example.

Both carbonyl compounds and acid derivatives though they contain grouping yet the reactions given by them are entirely different. As Aldehydes and Ketones give addition product with a nucleophile, while carboxylic acid derivatives give nucleophilic acyl substitution through addition/elimination mechanism. Where X- = -Cl - O-overset(O)overset(||)C-R-OR, -NR(R) etc. Why aldeydes and Ketones give nucleophilic addition reaction while acid derivatives prefer nucleophilic acyl substititution reaction?

What type of aldehydes and ketones undergo aldol condensation?