( ( ( ( The number ) ( of ( protons ( , ( ( neutrons and ) electrons ) ) ) ) ) ( an atom ) ) ( ( has ( determines ( ( what element ) ( it is ) ) ) ) . ) )
(ROOT (S (NP (NP (NP (DT The) (NN number)) (PP (IN of) (NP (NNS protons) (, ,) (NNS neutrons) (CC and) (NNS electrons)))) (NP (DT an) (NN atom))) (VP (VBZ has) (VP (VBZ determines) (NP (NP (WP what) (NN element)) (SBAR (S (NP (PRP it)) (VP (VBZ is))))))) (. .)))
The number of protons, neutrons and electrons an atom has determines what element it is.
(ROOT (S (S (VP (TO To) (VP (VB determine) (NP (NP (DT the) (JJ atomic) (NN weight)) (PP (IN of) (NP (DT an) (NN element))))))) (, ,) (NP (PRP you)) (VP (MD should) (VP (VB add) (PRT (RP up)) (NP (NNS protons) (CC and) (NNS neutrons)))) (. .)))