( ( ( A molecule ) ( of ethene ) ) ( ( has ( ( ( five ( sigma bonds ) ) and ) ( one ( pi bond ) ) ) ) . ) )
(ROOT (S (NP (NP (DT A) (NN molecule)) (PP (IN of) (NP (NN ethene)))) (VP (VBZ has) (NP (NP (CD five) (NN sigma) (NNS bonds)) (CC and) (NP (CD one) (NN pi) (NN bond)))) (. .)))
A molecule of ethene has five sigma bonds and one pi bond.
(ROOT (S (NP (DT A) (JJ double) (NN bond)) (VP (VBZ consists) (PP (IN of) (NP (NP (CD one) (NN sigma) (NN bond)) (CC and) (NP (CD one) (NN pi) (NN bond))))) (. .)))