( ( ( ( Carbon-14 , ) ( ( an isotope ) ( with ( ( a half-life ) ( of ( 5715 years ) ) ) ) ) ) , ) ( ( has ( been ( widely ( used ( to ( ( date ( such materials ) ) ( as ( ( ( ( wood , ) ( archeological specimens ) ) , ) etc. ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Carbon-14)) (, ,) (NP (NP (DT an) (NN isotope)) (PP (IN with) (NP (NP (DT a) (NN half-life)) (PP (IN of) (NP (CD 5715) (NNS years)))))) (, ,)) (VP (VBZ has) (VP (VBN been) (VP (ADVP (RB widely)) (VBN used) (PP (TO to) (NP (NP (NN date) (JJ such) (NNS materials)) (PP (IN as) (NP (NP (NN wood)) (, ,) (NP (JJ archeological) (NNS specimens)) (, ,) (FW etc.)))))))) (. .)))
Carbon-14, an isotope with a half-life of 5715 years, has been widely used to date such materials as wood, archeological specimens, etc.
(ROOT (S (NP (NP (NNP Carbon) (CD 14) (NN isotope)) (PP (IN of) (NP (NN carbon)))) (VP (VBZ is) (ADVP (RB typically)) (VP (VBN used) (PP (TO to) (NP (NN date) (JJ ancient) (NNS items))))) (. .)))