( ( ( A substance ) ( that ( ( can not ) ( be ( ( broken down ) ( into ( chemically ( simpler components ) ) ) ) ) ) ) ) ( ( is ( ( ( an element ) ( A substance ) ) ( that ( ( can not ) ( be ( ( broken down ) ( into ( chemically ( simpler components ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT A) (NN substance)) (SBAR (WHNP (WDT that)) (S (VP (MD can) (RB not) (VP (VB be) (VP (VBN broken) (PRT (RP down)) (PP (IN into) (NP (CD chemically) (JJR simpler) (NNS components))))))))) (VP (VBZ is) (NP (NP (DT an) (NN element)) (NP (DT A) (NN substance)) (SBAR (WHNP (WDT that)) (S (VP (MD can) (RB not) (VP (VB be) (VP (VBN broken) (PRT (RP down)) (PP (IN into) (NP (CD chemically) (JJR simpler) (NNS components)))))))))) (. .)))
A substance that cannot be broken down into chemically simpler components is an element A substance that cannot be broken down into chemically simpler components.
(ROOT (S (NP (PRP You)) (VP (VBP call) (NP (NP (DT a) (NN substance)) (SBAR (WHNP (WDT that)) (S (VP (MD can) (RB not) (VP (VB be) (VP (VBN broken) (PRT (RP down)) (PP (TO to) (NP (JJ other) (NNS substances))) (PP (IN by) (NP (NP (NN chemical) (NNS reactions)) (NP (DT an) (NN element))))))))))) (. .)))