sentences: lighting a candle causes that candle to burn & burning is similar to combustion ->  lighting a candle causes the candle to combust  lighting a candle causes the candle to combust & a candle is made of wax ->  lighting a candle causes the wax in candle to combust  lighting a candle causes the wax in candle to combust & wax contains chemical energy & combustion means fire converts chemical energy into light energy and heat energy ->  combustion converts the chemical energy in wax into light and heat energy  combustion converts the chemical energy in wax into light and heat energy & energy transformation means one kind of energy changes into another kind of energy -> the energy transformation in wax is from chemical energy to light and heat energy