( ( ( The ( atomic weight ) ) ( of ( an element ) ) ) ( ( ( is generally ) ( ( the ( combined weight ) ) ( of ( ( protons and ) neutrons ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (JJ atomic) (NN weight)) (PP (IN of) (NP (DT an) (NN element)))) (VP (VBZ is) (ADVP (RB generally)) (NP (NP (DT the) (VBN combined) (NN weight)) (PP (IN of) (NP (NNS protons) (CC and) (NNS neutrons))))) (. .)))
The atomic weight of an element is generally the combined weight of protons and neutrons.
(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)))) (. .)))