During the week of January 3, 2012, the Purple science class executed four experiments that were meant to increase our knowledge on physical and chemical changes. The first lab conducted was an experiment called Laboratory Investigation. In this lab, students were to observe the physical and chemical properties of an unlit candle. They noted several physical properties like its color, texture, and size and that there were no chemical properties to be seen. Once the candle was lit, students noted its physical and chemical properties. They found two examples of them immediately. The candle was shrinking in size and a disgusting, burning fume began to emerge from the fire on the wax. Using this information, the students completed a worksheet that was handed to them.
The second lab also used a candle. The purpose of this experiment was to create carbon dioxide. The class had recently learned that fire lives off oxygen, so the best way to extinguish fire was to eliminate all of the oxygen. In this lab, students mixed vinegar with baking soda to created carbon dioxide. As soon as the baking soda landed on the vinegar, a tremendous bubbly solution was formed. The students quickly tilted the glass over the flame, without letting any liquid spill, and the flame was was put out. Chemical change is how a substance reacts to another substance. In this case, the fire was completely obliterated once it met the carbon dioxide.
The next day, students completed a lab called Marshmallow Fun, which involved, you guessed it, marshmallows and a Bunsen burner. None of the students had ever used a Bunsen burner before, so numerous kids were excited to burn substances with the scientific tool. Students first described how the small and large marshmallow looked, feet, and smelled. Then, each student ripped his/her small marshmallow in half and observed that what just occurred was a physical change. The students happily ate their marshmallow and by using a skewer, held the large marshmallow over the Bunsen burner. Once the marshmallow burned and turned partly black, the students were told to eat it. It tasted like ash and felt chalky. The students then realized that the large marshmallow had undergone a chemical change when it was burned. The final lab, called Observing Changes in Matter, took place on February 3, 2012. It was taken in two parts: Part A and Part B. Part A was quite simple. First, students noted the physical qualities of a sugar cube. Then, they used a mortar and pestle to crush two cubes to powder. This was a physical change because it changed the substance without involving another substance. Students then poured the powder into a cup of water and they watched it settle at the bottom of the cup. The students realized that the sugar was still present in the water because it tasted sweet. They predicted that if the water were to evaporate, the sugar would still remain at the bottom of the cup. In Part B, students took two sugar cubes and squished them into a test tube. Squished is the word because the sugar cubes were not a perfect fit, the students had to break some pieces off them in order to get them inside the test tube. Then, by using tongs, the test tube was held over the Bunsen burner. When the sugar cubes burned and turned black, a strange liquid started to form. Once the amount of the liquid enlarged to about three times the size of the original sugar cubes, the test tube was placed away from the Bunsen burner. When the test tube finally cooled, the students were allowed to break the test tube. Students then took note of the physical properties of the strange substance left inside the test tube. At the end of both parts, the students realized the difference between the two parts. Part A represented a physical change and Part B represented a chemical change.
This information of chemical and physical changes could help in everyday life because it is involved in many real life applications. If you worked in a factory that changed mineral gold into liquid gold and liquid gold into fine jewelry, you would have to know how this works in order for the process to be precise and perfect. Gold is so expensive now, so one little mistake costs a fortune. Also, if you worked the lumber industry, you would have to know about physical change because you are creating it all the time. Lumberjacks physically chop down trees and they use the blocks in order to create many different items. Physical and chemical changes are involved throughout your life and you need to know what they are in order to do your job the best you can.
Citation of my pictures:
http://thumb9.shutterstock.com/thumb_small/77287/77287,1178154098,1/stock-photo-one-lit-birthday-candle-isolated-over-black-3214380.jpg
http://www.robinage.com/files/activities/Flame%20Out!.jpg
http://www.dreier.com/blog/wp-content/uploads/2010/03/burning-marshmallow-02.jpg
No comments:
Post a Comment