( Atom ( ( ( is ( ( the ( smallest particle ) ) ( of ( an element ) ) ) ) ( Elements ( such ( as ( ( iron , ) ( ( ( oxygen , ) sulfur ) , ) ) ) ) ) ) ... ) )
(ROOT (SINV (ADVP (RB Atom)) (VP (VBZ is) (NP (NP (DT the) (JJS smallest) (NN particle)) (PP (IN of) (NP (DT an) (NN element))))) (NP (NP (NNP Elements)) (PP (JJ such) (IN as) (NP (NP (NN iron)) (, ,) (NP (NP (NN oxygen)) (, ,) (NP (NN sulfur)) (, ,))))) (: ...)))
Atom is the smallest particle of an element Elements such as iron, oxygen, sulfur, ...
(ROOT (S (NP (DT The) (NN element) (NN sulfur)) (VP (VBZ has) (NP (DT the) (JJ atomic) (NN number) (CD 16))) (. .)))