Better Students Ask More Questions.
How does a burning candle show both physical and chemical changes?
3 Answers | add yours
The physical change occurs when the heat displaces the bonds that solidify the wax. Upon cooling, the wax is able to form the bond again. The chemical changes are much more complex. The first change is that the heat (fire) consumes the oxygen and fuels the flame. This then leads to the production and emission of carbon dioxide from the flame. As a by-product of the wick burning, you will then achieve soot as another physical and chemical change. The soot is a by product of the wick (chemical) and leaves a solid product as the emit (physical).
Posted by kdburgess on May 19, 2010 at 1:50 AM (Answer #1)
(Level 2) Assistant Educator, Annotator
When a candle burns, there is both a physical and chemical reaction.
The physical change is quite obvious and in fact, it can be seen. When the candle burns, the wax slowly melts and the candle gets smaller and smaller. This wax, as can be seen, will drip onto the candle and stick to it. When this wax forms back into a solid and stays on the candle, that is another physical change that can occur.
The chemical reaction can be a little less obvious. The first is that the heat produced by the candle consumes both the oxygen around it, as well as the fuels coming from the flame. This will then lead to carbon dioxide emissions produced by the flame, which by the way should never be inhaled. This is the chemical change that takes place in the reaction.
Posted by yamaguchityler on February 11, 2014 at 11:01 PM (Answer #4)
Join to answer this question
Join a community of thousands of dedicated teachers and students.