( ( Each ( hydrogen atom ) ) ( ( has ( one electron ) ) ; ) )
(ROOT (S (NP (DT Each) (NN hydrogen) (NN atom)) (VP (VBZ has) (NP (CD one) (NN electron))) (: ;)))
Each hydrogen atom has one electron;
(ROOT (S (NP (EX There)) (VP (VBP are) (NP (NP (CD one) (NNS electrons)) (PP (IN in) (NP (DT the) (NN hydrogen) (NN atom))))) (. .)))