( ( The atom ) ( ( is ( composed ( of ( ( subatomic particles ) ( called ( ( ( ( ( protons , ) neutrons ) , ) and ) electrons ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN atom)) (VP (VBZ is) (VP (VBN composed) (PP (IN of) (NP (NP (JJ subatomic) (NNS particles)) (VP (VBN called) (NP (NP (NNS protons)) (, ,) (NP (NNS neutrons)) (, ,) (CC and) (NP (NNS electrons)))))))) (. .)))
The atom is composed of subatomic particles called protons, neutrons , and electrons.
(ROOT (S (NP (NP (DT The) (NN number)) (PP (IN of) (NP (NNS neutrons)))) (VP (MD can) (VP (VB vary) (PP (IN between) (NP (NP (NNS atoms)) (PP (IN of) (NP (DT the) (JJ same) (NN element))))))) (. .)))