( ( Burning ( of wood ) ) ( ( ( is ( a ( chemical change ) ) ) ( as ( ( ( new substances ) ( which ( ( can not ) ( be ( ( changed back ) ( -LRB- ( ( ( ( e.g. ( carbon dioxide ) ) , ) ( water vapor ) ) -RRB- ) ) ) ) ) ) ) ( are formed ) ) ) ) . ) )
(ROOT (S (NP (NP (NN Burning)) (PP (IN of) (NP (NN wood)))) (VP (VBZ is) (NP (DT a) (JJ chemical) (NN change)) (SBAR (IN as) (S (NP (NP (JJ new) (NNS substances)) (SBAR (WHNP (WDT which)) (S (VP (MD can) (RB not) (VP (VB be) (VP (VBN changed) (ADVP (RB back)) (PRN (-LRB- -LRB-) (NP (NP (JJ e.g.) (NN carbon) (NN dioxide)) (, ,) (NP (NN water) (NN vapor))) (-RRB- -RRB-)))))))) (VP (VBP are) (VP (VBN formed)))))) (. .)))
Burning of wood is a chemical change as new substances which cannot be changed back (e.g. carbon dioxide, water vapor) are formed.
(ROOT (S (NP (NNP Wood) (NNP burning)) (VP (VBZ is) (NP (NP (DT an) (NN example)) (PP (IN of) (NP (NP (DT a) (JJ different) (NN substance)) (VP (VBG being) (VP (VBN formed))))))) (. .)))