Physical and Chemical Changes

Who knew so much could occur just by lighting
a candle? In class, we did a lab which taught my group about chemical and physical changes. First, we lit a birthday candle and the wax started to melt. The wax changed its appearance by absorbing the heat given off by the flame. This was an endothermic change, a change which absorbs energy. The wax was taking in the heat produced by the flame, therefore, it transformed into a liquid. The liquid’s molecules had more “space” than when it was in solid form.

Furthermore, a chemical change took place since smoke was present. The wax combined with the flame’s heat to emit smoke. A new substance formed with a different molecular makeup.

Did you know that an exothermic change occurred too? An exothermic change, energy that is released, was taking place when the flame was burning since it was giving off heat.

In order to keep something burning, oxygen must be present. My group combined vinegar and baking soda. This chemical reaction created a new substance called carbon dioxide. When we placed the carbon dioxide near the flame, it extinguished since oxygen was no longer present, therefore this process was combustion.

I did some further research on this subject and came across combustion. Combustion is the burning of a substance. In this case, my group burned the wick of a birthday candle.

As one can see, many things took place when my group did this lab. I thought this lab was very interesting. Now I have a better understanding of chemical and physical changes.




I got my information from here