( ( The equation ) ( ( can ( be ( ( ( solved exactly ) ( for ( the ( hydrogen atom ) ) ) ) ( with ( ( ( one proton ) and ) ( one electron ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN equation)) (VP (MD can) (VP (VB be) (VP (VBN solved) (ADVP (RB exactly)) (PP (IN for) (NP (DT the) (NN hydrogen) (NN atom))) (PP (IN with) (NP (NP (CD one) (NN proton)) (CC and) (NP (CD one) (NN electron))))))) (. .)))
The equation can be solved exactly for the hydrogen atom with one proton and 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))))) (. .)))