( ( All ( of ( the elements ) ) ) ( ( ( ( have ( ( some isotopes ) ( that ( ( are radioactive ) ( -LRB- ( radioisotopes -RRB- ) ) ) ) ) ) , ) ( although ( ( ( not all ) ( of ( these radioisotopes ) ) ) ( occur naturally ) ) ) ) . ) )
(ROOT (S (NP (NP (DT All)) (PP (IN of) (NP (DT the) (NNS elements)))) (VP (VBP have) (NP (NP (DT some) (NNS isotopes)) (SBAR (WHNP (WDT that)) (S (VP (VBP are) (ADJP (JJ radioactive)) (PRN (-LRB- -LRB-) (NP (NNS radioisotopes)) (-RRB- -RRB-)))))) (, ,) (SBAR (IN although) (S (NP (NP (RB not) (DT all)) (PP (IN of) (NP (DT these) (NNS radioisotopes)))) (VP (VBP occur) (ADVP (RB naturally)))))) (. .)))
All of the elements have some isotopes that are radioactive (radioisotopes), although not all of these radioisotopes occur naturally.
(ROOT (S (NP (DT A) (-LRB- -LRB-) (NN n) (-RRB- -RRB-) (NNS radioisotopes)) (VP (VBZ is) (NP (NP (DT an) (NN isotope)) (SBAR (WHNP (WDT that)) (S (VP (VBZ is) (ADJP (JJ radioactive))))))) (. .)))