Which of the following is an accurate characteristic of an aldehyde functional group?

• A. Contains a $\mathrm{carbonyl}$ group bonded to a $\mathrm{hydrogen}$ atom
• B. Contains a $\mathrm{carbonyl}$ group bonded to two $\mathrm{alkyl}$ groups
• C. Contains a $\mathrm{hydroxyl}$ group bonded to a $\mathrm{carbon}$ atom
• D. Contains a $\mathrm{nitrogen}$ atom bonded to a $\mathrm{carbonyl}$ group

Answer: (A)

Verified step by step guidance

1. Identify the functional group in question: an aldehyde.
2. Recall the structure of an aldehyde: it contains a carbonyl group (C=O).
3. Understand that in an aldehyde, the carbonyl carbon is bonded to at least one hydrogen atom.
4. Differentiate aldehydes from ketones, which have the carbonyl carbon bonded to two alkyl groups.
5. Recognize that the presence of a hydroxyl group or a nitrogen atom bonded to a carbonyl group is characteristic of other functional groups, such as alcohols or amides, not aldehydes.