( Beryllium ( ( is ( ( the ( ( only even ) ( atomic ( numbered element ) ) ) ) ( with ( a ( single ( stable ( isotope 9Be ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Beryllium)) (VP (VBZ is) (NP (NP (DT the) (ADJP (RB only) (RB even)) (JJ atomic) (NN numbered) (NN element)) (PP (IN with) (NP (DT a) (JJ single) (JJ stable) (NN isotope) (NNS 9Be))))) (. .)))
Beryllium is the only even atomic numbered element with a single stable isotope 9Be.
(ROOT (S (NP (NP (DT The) (JJ low) (JJ atomic) (NN number)) (PP (IN of) (NP (NN beryllium)))) (VP (VBZ allows) (S (NP (PRP it)) (VP (TO to) (VP (VB absorb) (NP (NNPS x-rays)))))) (. .)))