What type of compound is characterized by the presence of a carbonyl group bonded to two alkyl groups?

The compound described is a ketone, which is characterized by a carbonyl group (C=O) that is bonded to two alkyl groups. In ketones, the carbonyl carbon is located within the carbon chain rather than at the end, which distinguishes it from aldehydes, where the carbonyl group is attached to at least one hydrogen atom, making aldehydes typically present at the terminal position of the carbon chain.

In ketones, this structure can be represented as R2C=O, where R represents the alkyl groups. This allows for a variety of structural possibilities based on the nature of these alkyl groups, giving ketones a versatile role in organic chemistry.

The other options pertain to different types of compounds that do not fit the description of having two alkyl groups bonded to a carbonyl. Aldehydes have only one alkyl group and a hydrogen atom attached to the carbonyl carbon. Amines are characterized by nitrogen atoms bonded to carbon atoms, and esters contain a carbonyl directly attached to an oxygen atom as well as another alkyl or aryl group. Thus, these characteristics affirm that ketones are the only compounds that meet the criteria provided in the question.