Observing a Candle
The first thing we did in this lab was observe the candle. We did this so we could better understand what kind of materials we are dealing with and so we could compare after we finished manipulating the candle. We observed that the candle was hard, waxy, and solid. Next, we lit the candle. Whenever you are burning something, the process is called combustion. As the candle was lit, the wax, which was solid, began to melt, becoming a liquid (physical change). The candle was chemically changed when the heat and the oxygen and the wick of the candle produced carbon dioxide.
Pouring a Gas
First we lit a large white candle. Next, we mixed vinegar and baking soda together so that it would produce carbon dioxide. As we held the vinegar and baking soda mixture to the flame, the flame would go out. This is because fire needs oxygen to "live" and when the carbon dioxide took away that oxygen, the fire had to go out.
Marshmallow Fun
I enjoyed this lab very much. First we had to observe a large and small marshmallow. Then we ripped the small marshmallow, causing a physical change. Next, we had to eat our small marshmallow. This was a physical change because we tore the marshmallow with our teeth and a chemical change because our stomach turned the food into nutrients for our body. Using a Bunsen burner, we roasted the larger marshmallow. The outside layer because blacked and tasted bitter unlike the original marshmallow taste (sweet). We caused a chemical change to the larger marshmallow because we burned it. I think that the marshmallow was a solid because it had a definite volume and shape. It's molecules were also closely packed together and it couldn't really move.
Observing Changes in Matter
The final lab that we did had to do with burning sugar. Once again, we had to observe a sugar cube (size, shape, color, taste, hardness, texture). Then we physically changed the sugar because we crushed it with a mortar and pestle. When the sugar was mixed with the water, you couldn't see the sugar anymore. The sugar was still there, it just dissolved in the water. When we burned the sugar, water was condensing to the sides of the test tube because the water from the sugar was evaporating. Smoke was also coming out of the test tube. First, the sugar turned into a thick liquid. Then it slowly turned to black. When we removed the test tube from the Bunsen burner, it hardened. The process of burning the sugar was called caramelization. When we cracked open the test tube, we observed what was left over from the burnt sugar (carbon) which was a result of a chemical change.
In Conclusion...
I learned a lot from these labs. I learned the difference between a physical and chemical change and the different states of matter there are. In addition, these labs taught me the importance of observing and comparing when doing labs so you can tell the difference from the "before" and "after". I can use the skills that I've learned later in life. For example, if I ever need to make candy, I'll know how to burn sugar. Also, I can now classify different things as either solid, liquid, or gas. Furthermore, if I ever need to light a fire, I'll know that there must be oxygen in order for there to be a flame. 