( ( ( A representation ) ( of ( ( the composition ) ( of ( ( a substance ) ( that ( ( ( ( uses ( ( the ( atomic symbols ) ) ( of ( the ( elements present ) ) ) ) ) , ) and ) uses ) ) ) ) ) ) ) ( ( subscripts ( to ( show ( ( the ( relative proportions ) ) ( of ( each atom ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT A) (NN representation)) (PP (IN of) (NP (NP (DT the) (NN composition)) (PP (IN of) (NP (NP (DT a) (NN substance)) (SBAR (WHNP (WDT that)) (S (VP (VP (VBZ uses) (NP (NP (DT the) (JJ atomic) (NNS symbols)) (PP (IN of) (NP (DT the) (NNS elements) (NN present))))) (, ,) (CC and) (VP (VBZ uses)))))))))) (VP (VBZ subscripts) (S (VP (TO to) (VP (VB show) (NP (NP (DT the) (JJ relative) (NNS proportions)) (PP (IN of) (NP (DT each) (NN atom)))))))) (. .)))
A representation of the composition of a substance that uses the atomic symbols of the elements present, and uses subscripts to show the relative proportions of each atom.
(ROOT (S (SBAR (IN If) (S (NP (NP (RB only) (CD one) (NN atom)) (PP (IN of) (NP (DT a) (JJ specific) (NN type)))) (VP (VBZ is) (ADJP (JJ present))))) (NP (DT a) (NN subscript)) (VP (VBZ is) (RB not) (VP (VBN used))) (. .)))