( ( This molecule ) ( ( joins ( ( ( others ( and ( forms bubbles ) ) ) ( of ( hydrogen gas ) ) ) ( that ( ( ( rise ( through ( the water ) ) ) , ) ( ( ( making room ) ( for ( more water ) ) ) ( to ( ( ( contact ( the cathode ) ) and ) ( form ( more hydrogen ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT This) (NN molecule)) (VP (VBZ joins) (NP (NP (NNS others) (CC and) (NNS forms) (NNS bubbles)) (PP (IN of) (NP (NN hydrogen) (NN gas))) (SBAR (WHNP (WDT that)) (S (VP (VBP rise) (PP (IN through) (NP (DT the) (NN water))) (, ,) (S (VP (VBG making) (NP (NN room)) (PP (IN for) (NP (JJR more) (NN water))) (S (VP (TO to) (VP (VP (VB contact) (NP (DT the) (NN cathode))) (CC and) (VP (VB form) (NP (JJR more) (NN hydrogen))))))))))))) (. .)))
This molecule joins others and forms bubbles of hydrogen gas that rise through the water, making room for more water to contact the cathode and form more hydrogen.
(ROOT (S (NP (NNP Hydrogen)) (VP (VBZ is) (PP (IN in) (NP (NP (NN gas) (NN form)) (PP (IN at) (NP (NN room) (NN temperature)))))) (. .)))