( Chemically ( , ( carotenes ( ( are ( ( polyunsaturated hydrocarbons ) ( containing ( ( ( ( ( ( ( 40 ( carbon atoms ) ) ( per molecule ) ) , ) ( ( variable numbers ) ( of ( hydrogen atoms ) ) ) ) , ) and ) ( no ( other elements ) ) ) ) ) ) . ) ) ) )
(ROOT (S (ADVP (RB Chemically)) (, ,) (NP (NNS carotenes)) (VP (VBP are) (VP (VBN polyunsaturated) (NP (NNS hydrocarbons)) (S (VP (VBG containing) (NP (NP (NP (CD 40) (NN carbon) (NNS atoms)) (PP (IN per) (NP (NN molecule)))) (, ,) (NP (NP (JJ variable) (NNS numbers)) (PP (IN of) (NP (NN hydrogen) (NNS atoms)))) (, ,) (CC and) (NP (DT no) (JJ other) (NNS elements))))))) (. .)))
Chemically, carotenes are polyunsaturated hydrocarbons containing 40 carbon atoms per molecule, variable numbers of hydrogen atoms, and no other elements.
(ROOT (S (NP (NNS Hydrocarbons)) (VP (VBP are) (VP (VBN made) (PP (IN of) (NP (NP (CD one) (NN carbon)) (CC and) (NP (CD four) (NN hydrogen) (NNS atoms)))))) (. .)))
Hydrocarbons are made of one carbon and four hydrogen atoms.