( ( An ( ordinary ( carbon atom ) ) ) ( ( has ( ( ( six protons ) and ) ( ( six neutrons ) ( in ( its nucleus ) ) ) ) ) ; ) )
(ROOT (S (NP (DT An) (JJ ordinary) (NN carbon) (NN atom)) (VP (VBZ has) (NP (NP (CD six) (NNS protons)) (CC and) (NP (NP (CD six) (NNS neutrons)) (PP (IN in) (NP (PRP$ its) (NN nucleus)))))) (: ;)))
An ordinary carbon atom has six protons and six neutrons in its nucleus;
(ROOT (S (NP (DT All) (NN carbon) (NNS atoms)) (VP (VBP have) (NP (CD six) (NNS protons))) (. .)))