Carbonyl compounds, like aldehydes, ketones, and carboxylic acids, are important in making other organic molecules. They have some special properties that make them react in unique ways.

1. Nucleophilic Addition:

   • Aldehydes and ketones can have something called nucleophilic addition. This means that a nucleophile (which is a type of reactive particle) can attach itself to the carbon atom in the carbonyl group (the C=O part).
   • For example, when a chemical called sodium borohydride (NaBH4) meets an aldehyde, it helps turn the carbonyl group into an alcohol.

2. Condensation Reactions:

   • Carbonyl compounds can also take part in condensation reactions.
   • In a reaction between an aldehyde and an amine (which is another type of compound), they can form something called an imine. This shows how carbonyls can connect with other groups of molecules.

3. Acidity and Reactivity:

   • Carboxylic acids are special because they can give away protons (which are tiny particles) due to their acidic nature. This ability affects how they react with other chemicals.
   • For instance, acetic acid can participate in reactions with alcohols to create esters.

These different types of reactions show just how important carbonyl compounds are in creating organic molecules. They help scientists build complex structures in chemistry.