( It ( ( ( ( consists ( of ( ( a ( central core ) ) ( of ( ( protons and ) neutrons ) ) ) ) ) , ) ( called ( the nucleus ) ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBZ consists) (PP (IN of) (NP (NP (DT a) (JJ central) (NN core)) (PP (IN of) (NP (NNS protons) (CC and) (NNS neutrons))))) (, ,) (VP (VBN called) (NP (DT the) (NN nucleus)))) (. .)))
It consists of a central core of protons and neutrons , called the nucleus .
(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))))) (. .)))