What type of bond forms between carbon and oxygen in carbonyl compounds?

In carbonyl compounds, the bond that forms between carbon and oxygen is a double covalent bond. This type of bond involves the sharing of four electrons, with two electrons contributed by the carbon atom and two electrons contributed by the oxygen atom. The presence of this double bond is a defining characteristic of carbonyl groups, which are found in compounds such as aldehydes, ketones, carboxylic acids, and esters.

The double bond contributes to the reactivity of carbonyl compounds, as it makes the carbon atom electrophilic, allowing it to participate in various chemical reactions. The distinction of a carbonyl group is essential in organic chemistry because it enables the classification and understanding of a wide range of organic molecules based on their functional groups.