Combustion is a challenging concept for students to understand. At the visible scale, it seems like matter disappears as it burns. A match burns and gets shorter. A gasoline tank becomes empty. A candle burns until all the wax is gone. How do students make sense of these experiences, especially when they do not fully understand gases as a form of matter? All these experiences can be explained by fuels (such as wax, wood, or fossil fuels) being oxidized and giving off carbon dioxide and water as products. So how do teachers use everyday experiences, such as burning a match or a candle, to help students understand that solid or liquid fuels become gases? By simply taking an everyday experience, like a burning candle, and asking students to explain where the wax material goes, you can open the door for rich discussion about combustion.
Watch this video of 5th grade students in South Gate, California—a coastal community. The purpose of this classroom video is to see students discuss what happens to materials and energy as a candle burns.
For additional classroom context, video analysis, and reflection opportunities, read the Picture of Practice page for "A Burning Candle" in the Changing Climate Environmental Literacy Teacher Guide, page 56.