( ( ( The nucleus ) ( of ( the atom ) ) ) ( ( is ( composed ( of ( ( protons and ) neutrons ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN nucleus)) (PP (IN of) (NP (DT the) (NN atom)))) (VP (VBZ is) (VP (VBN composed) (PP (IN of) (NP (NNS protons) (CC and) (NNS neutrons))))) (. .)))
The nucleus of the atom is composed of protons and neutrons.
(ROOT (S (NP (NNS Protons) (CC and) (NNS neutrons)) (VP (VBP are) (VP (VBN located) (PP (IN in) (NP (DT the) (JJ central) (NN nucleus))))) (. .)))