The acryl group is one of the functional groups sorted in the chemical class of acryl where one of four hydrogen atoms in ethene is replaced with a different functional group. It differs from vinyl in that compounds including acryl in their names have formulas in which their substituents are nitrile groups, adding onitrile after acryl for the name of the acryl compounds like acrylonitrile. Also, carboxyl groups of acrylic acid can react with ammonia adding amide after acryl for the name of the acryl compounds like acrylamide or alcohol adding ate after acryl for the name of the acryl compounds like acrylate. Note: when group name whose head letter is consonant follows, the variant form of acrylo precedes it meanwhile the original term acryl precedes vowel letter.