Look at the following examples and decide what phase change is involved. That's why water doesn't get hotter as it boils. The temperature remains constant until the phase change is complete. To better understand physical changes break a small piece off the bottom of a candle and describe 4 ways in which the candle has changed physically. You may want to use a magnifying glass or hand lens to improve your observations.
Chemical changes are changes substances undergo when they become new or different substances.
For example, the fireworks we see on the 4th of July are actually metals such as magnesium and copper that change chemically as they light up the night skies with their fantastic colors. To identify a chemical change look for observable signs such as color change, bubbling and fizzing, light production, smoke, and presence of heat. To experience chemical change you will need a candle and a match. First put on your safety glasses then light your candle. Write down 4 observations.