( ( An atom ) ( ( is ( distinguished ( by ( number ( of ( ( protons and ) neutrons ) ) ) ) ) ) ; ) )
(ROOT (S (NP (DT An) (NN atom)) (VP (VBZ is) (ADJP (JJ distinguished) (PP (IN by) (NP (NP (NN number)) (PP (IN of) (NP (NNS protons) (CC and) (NNS neutrons))))))) (: ;)))
An atom is distinguished by number of protons and neutrons;
(ROOT (S (S (S (VP (VBG Adding) (NP (NP (NP (DT the) (NN number)) (PP (IN of) (NP (NNS protons)))) (CC plus) (NP (NP (DT the) (NN number)) (PP (IN of) (NP (NP (NNS neutrons)) (PP (IN in) (NP (DT an) (NN atom))))))))) (VP (VBZ decides) (NP (PRP$ its) (JJ approximate) (NN mass)))) (: ;) (S (NP (JJ atomic) (NN number)) (VP (VBZ is) (NP (NP (DT another) (NN word)) (PP (IN for) (NP (DT this) (NN value)))))) (. .)))