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