( Noble ( gas compound ) )
(ROOT (NP (NP (NNP Noble)) (NP (NN gas) (NN compound))))
Noble gas compound
(ROOT (S (NP (NNP Neon)) (VP (VBZ is) (NP (NP (DT an) (NN example)) (PP (IN of) (NP (JJ noble) (NN gas))))) (. .)))