 |
| Marshmallow on Fire |
 |
| Sugar Cubes |
In science class last week we had a lot of fun with fire. To begin with, we first all gathered around a candle and observed its chemical and physical properties by setting the candle on fire. To add on, then we made carbon dioxide by mixing vinegar and baking soda. Next, then our class had fun burning marshmallows. We used Bunsen burners to burn the marshmallows. We were observing chemical change during that experiment. Lastly, we had then done an experiment that included burning sugar to make carbon. In our first experiment we had observed a lit and a unlit candle. At first we had described it as carved because it was shaped in a swirl, also it was thin and small because it was mainly used for purposes that it needed to be thin and small, it was also easily breakable because of the material the candle was made of, and it was white. The group that I was in used sight and touch to figure out the physical properties. To add on, the difference between physical and chemical properties are that chemical cannot be identified by any of the five senses and physical properties can be. One chemical change observed was that combustion occurred when the candle was lit. Next, we all know that fires live of off air. Air always helps a flame live until it runs out of space and things to burn on. In our next experiment, our group took vinegar and baking soda to make carbon dioxide. First, we took some of the baking soda and dropped it in the vinegar and as soon as the baking soda touched the vinegar, the substance started making a gas. To add on, as it was held pointing at the lit candle, the fire suddenly died because of the carbon dioxide. It showed chemical reaction of combustion binding with other gases. For instance, the fire's fuel was air or oxygen, but the fires killer was carbon dioxide or co2. The second to last experiment our class did was burning marshmallows. First of all, we observed the small marshmallow for its physical properties. The physical properties of the small marshmallows were that it was small, white, fluffy, soft, and it was in the shape of a cylinder. Then we had to rip it in half to observe physical change. Then we tasted it and the taste was sweet and it felt soft inside my mouth. Then we observed the physical changes of the large marshmallow. It had all the same physical properties of the smaller marshmallow except that it was bigger in size. Then to observe chemical change we placed the marshmallow on the fire. the marshmallow caught on fire and started to burn. As it burned the outside which was white started turning black and it started melting from the inside. This is an example of chemical change. Not only did chemical change occur but also, there was physical change inside the marshmallow. When the marshmallow started getting warmer from the outside, the outside had its own reaction to the heat, but the inside started melting as soon as the heat was added. Then as we ate the big marshmallow the outside tasted like ash, however, the inside tasted sweet and creamy. Although we burned the marshmallow, and the inside melted a little, the marshmallow was still in a form of a solid. The heat just made the molecules vibrate faster and faster. Finally, our last experiment is when we chemically change sugar into a new substance. We first needed to gather a test tube, 4 sugar cubes, a glass of water, a straw, mortar and pestle, Bunsen burner, and tongs. First, we observed the sugar cubes, it was, white, a cube, sweet, small,hard, crystalline(made up of crystals), and it was rough. Then, we take the mortar and pestle and crushed two sugar cubes, after that we poured the sugar into the water and stirred it with a straw. Then we observed the sugar water but the sugar was barely visible so then we tasted the water and the sugar was still present. In the next part we started to burn sugar. First we had to crush the sugar partially so that it would fit in the test tube. As we put the test tube over the Bunsen burner, it seemed as if the sugar started melting. But then we realised that it was called caramelizing. But then it started to grow and grow until we took it of the fire. It turned into a black color and it smelled bad. Our teacher came to our table and broke the test tube so we could observe the substance. We then observed it properly and said it was a group of small crystals, black, no taste, and fragile. The sugar has changed from it being in a cube changing into a new substance. The new substance was classified as carbon. This can and cannot help in real life, it can help with fires, but it informs us about how to make new substances by either physically changing the main substance or chemically. It helps chemist create new medicines or vaccines. It also helps in the browning of food. Also you know better than anyone around the camp fire why the outside of the marshmallow turns black and the inside melts. For this entire week my class played with fire.
http://www.exploratorium.edu/cooking/candy/caramels-story.html
http://www.stevespanglerscience.com/experiment/invisible-fire-extinguisher
