( Water ( ( is ( ( a ( chemical compound ) ) ( that ( is ( created ( when ( ( the ( element hydrogen ) ) ( reacts ( with ( the ( element oxygen ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Water)) (VP (VBZ is) (NP (NP (DT a) (JJ chemical) (NN compound)) (SBAR (WHNP (WDT that)) (S (VP (VBZ is) (VP (VBN created) (SBAR (WHADVP (WRB when)) (S (NP (DT the) (NN element) (NN hydrogen)) (VP (VBZ reacts) (PP (IN with) (NP (DT the) (NN element) (NN oxygen)))))))))))) (. .)))
Water is a chemical compound that is created when the element hydrogen reacts with the element oxygen.
(ROOT (S (NP (NNP Water)) (VP (VBZ is) (NP (NP (DT an) (NN oxide)) (PP (IN of) (NP (NN hydrogen))))) (. .)))