( ( Elements ( of ATOM ) ) ( ( are ( ( ( called atoms ) and ) ( denoted ( by a ) ) ) ) . ) )
(ROOT (S (NP (NP (NNS Elements)) (PP (IN of) (NP (NNP ATOM)))) (VP (VBP are) (VP (VP (VBN called) (NP (NNS atoms))) (CC and) (VP (VBN denoted) (PP (IN by) (NP (NNP a)))))) (. .)))
Elements of ATOM are called atoms and denoted by a .
(ROOT (S (NP (PRP You)) (VP (VBP call) (NP (NP (NNS elements)) (SBAR (WHNP (WDT that)) (S (VP (VBP contain) (NP (NP (JJ only) (NNS atoms)) (PP (IN of) (NP (NP (CD one) (NN type)) (PP (IN of) (NP (NN element) (NN native) (NNS elements))))))))))) (. .)))