Question

how are the carboxyl and amide functional groups alike and different?
the carboxyl and amide both have carbonyl groups. the amide has a fluorine atom attached to the carbonyl carbon atom; the carboxyl group has a hydrocarbon group attached to the carbonyl carbon atom.
the carboxyl and amide both have carbonyl groups. the amide has a phosphorous atom attached to the carbonyl carbon atom; the carboxyl group has a phosphate group attached to the carbonyl carbon atom.
the carboxyl and amide both have carbonyl groups. the amide has a sodium atom attached to the carbonyl carbon atom; the carboxyl group has a thiol group attached to the carbonyl carbon atom.
the carboxyl and amide both have carbonyl groups. the amide has a potassium atom attached to the carbonyl carbon atom; the carboxyl group has a chromate group attached to the carbonyl carbon atom.
the carboxyl and amide both have carbonyl groups. the amide has a nitrogen atom attached to the carbonyl carbon atom; the carboxyl group has a hydroxyl group attached to the carbonyl carbon atom.

Explanation:

The carboxyl group has the formula -COOH (where -OH is the hydroxyl group attached to the carbonyl carbon). The amide group has the formula -CONH₂ (where -NH₂ has a nitrogen atom attached to the carbonyl carbon). Both contain a carbonyl group (C=O). The other options mention incorrect atoms/groups (fluorine, phosphorus, sodium, potassium, phosphate, thiol, chromate) attached to the carbonyl carbon for amide and carboxyl groups.

Answer:

The carboxyl and amide both have carbonyl groups. The amide has a nitrogen atom attached to the carbonyl carbon atom; the carboxyl group has a hydroxyl group attached to the carbonyl carbon atom.