lighting a candle causes that candle to burn & fire causes burning ->  lighting a candle is using fire to cause the candle to burn  lighting a candle is using fire to cause the candle to burn & fire is a kind of chemical reaction ->  lighting a candle causes the candle to undergo chemical reaction  lighting a candle causes the candle to undergo chemical reaction & chemical change is a kind of chemical reaction -> lighting a candle causes the candle to undergo chemical change