( ( ( Atoms ( of hydrogen ) ) ( -LRB- ( H -RRB- ) ) ) ( ( have ( ( one ( valence electron ) ) ( in ( their ( first ( electron shell ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NP (NNS Atoms)) (PP (IN of) (NP (NN hydrogen)))) (PRN (-LRB- -LRB-) (NP (NNP H)) (-RRB- -RRB-))) (VP (VBP have) (NP (NP (CD one) (JJ valence) (NN electron)) (PP (IN in) (NP (PRP$ their) (JJ first) (NN electron) (NN shell))))) (. .)))
Atoms of hydrogen (H) have one valence electron in their first electron shell .
(ROOT (S (NP (EX There)) (VP (VBP are) (NP (NP (CD one) (NNS electrons)) (PP (IN in) (NP (DT the) (NN hydrogen) (NN atom))))) (. .)))