( ( Physical studies ) ( ( include ( ( ( ( ( the ( one ( and ( two ( electron atoms ) ) ) ) ) , ) ( the ( hydrogen atom ) ) ) and ) ( ( ( ( ( the alkalis ) , ) ( hydrogen molecule ) ) and ) ( molecular bond ) ) ) ) . ) )
(ROOT (S (NP (JJ Physical) (NNS studies)) (VP (VBP include) (NP (NP (DT the) (CD one) (CC and) (CD two) (NN electron) (NNS atoms)) (, ,) (NP (DT the) (NN hydrogen) (NN atom)) (CC and) (NP (NP (DT the) (NNS alkalis)) (, ,) (NP (NN hydrogen) (NN molecule)) (CC and) (NP (JJ molecular) (NN bond))))) (. .)))
Physical studies include the one and two electron atoms, the hydrogen atom and the alkalis, hydrogen molecule and molecular bond.
(ROOT (S (NP (EX There)) (VP (VBP are) (NP (NP (CD one) (NNS electrons)) (PP (IN in) (NP (DT the) (NN hydrogen) (NN atom))))) (. .)))