( ( c -RRB- ) ( Isotopes ( ( are ( atoms ( of ( ( an element ) ( that ( have ( ( different numbers ) ( of protons ) ) ) ) ) ) ) ) . ) ) )
(ROOT (S (LST (LS c) (-RRB- -RRB-)) (NP (NNP Isotopes)) (VP (VBP are) (NP (NP (NNS atoms)) (PP (IN of) (NP (NP (DT an) (NN element)) (SBAR (WHNP (WDT that)) (S (VP (VBP have) (NP (NP (JJ different) (NNS numbers)) (PP (IN of) (NP (NNS protons))))))))))) (. .)))
c) Isotopes are atoms of an element that have different numbers of protons.
(ROOT (S (S (NP (PRP You)) (VP (VBP call) (NP (NP (DT a) (NN substance)) (SBAR (WHNP (WDT that)) (S (VP (MD can) (RB not) (VP (VB be) (VP (VBN separated) (PP (IN into) (NP (NP (JJR smaller) (NNS pieces)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ is) (ADVP (RB also)) (VP (VBN defined) (PP (IN by) (NP (NP (DT the) (NN number)) (PP (IN of) (NP (NNS protons))))))))))))))))))) (NP (PRP it)) (VP (VP (VBZ has)) (, ,) (NP (DT a) (PRN (-LRB- -LRB-) (NP (NN n)) (-RRB- -RRB-)) (NN element))) (. .)))