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. The word acryl as preffix in stead of vinyl as noun is used when the substituting functional group is particular one. For example, vinyl group bonding with nitrile group is called acrylonitrile but not vinyl nitrile, adding onitrile after acryl for the name of the acryl compounds. 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.