What I Learned from the Teaching Lessons for Chapters 8 & 9


Science 8


January 26, 2004


From the experiments performed during the two Science class periods, I learned a lot about all different kinds of solids, liquids, gases, and the classification of matter. Through group work, teaching, and learning at the same time, I was able to gain a large amount of valuable scientific knowledge, allowing me to enjoyably explore further on the subjects in chapters eight and nine. The group work was good for us as well, I can say. When working together as a whole group in contrast to working by myself, I was able to learn how to become a better part of a team instead of working alone.


During the two days of our teaching, each group performed different experiments to accompany their explanations. For instance, group one, Krispy Kreme, did a wonderful job in explaining their two sections (8.3 and 8.4) dealing with changes in state and behavior of gases. In lesson 8.3, Krispy Kreme explained how to identify a change in state, defining evaporation (when a liquid changes to gas), condensation (when gas changes to liquid), using steam on a mirror after a shower as an example. Another vocabulary word explained was heat of fusion (amount of energy needed to change a material from solid to liquid). For 8.4, Krispy Kreme taught the vocabulary words – pressure (amount of force exerted per unit of area, or p=f/a) and Pascal (Pa; the SI unit of pressure) Next, Krispy Kreme taught Boyle’s law (decreasing the volume of a container of gas causes the pressure of gas to increase if the temperature does not change, and increasing the volume causes the pressure to drop) and Charles’ law (volume of gas increases with increasing temperature if the temperature does not change and the volume of a gas shrinks with decreasing temperature). Two beakers of hot water on hotplates were used to accurately demonstrate pressure, condensation, and evaporation as a start of their experiments. The Krispy Kreme demonstrated Boyle’s law with balloons, which were blown up and then popped to show the vast change in pressure. They then explained the concept of Charles’ law using the example of a hot air balloon. Altogether the group did a fine job and I was able to understand their concepts quite clearly.


Group two was our table, the What’s-A-Faces. We taught lesson 9.1, tactfully explaining elements such as matter, substances, and mixtures, showing a granite rock from Colorado as an example of a compound (two or more kinds of atoms) and making corn soup to show heterogeneous mixtures (unevenly mixed). Group three, the Koolies, did a couple of experiments as well while teaching lessons 8.2 and 8.5 about water pollution and the uses of fluids. Their vocabulary for 8.2 included polluted water (water that contains such high levels of unwanted materials that it is unacceptable for drinking or other specific purposes) and thermal pollution (excess heat in water). The Koolies carefully explained water pollution and all the causes within (fertilizers, pesticides, herbicides, etc.), using a beaker of pure water and food coloring to demonstrate how each kind of waste pollutes the water from crystal clear to almost completely black. For lesson 8.5, Koolies clearly classified buoyant force (ability of a liquid or gas to exert an upward force an object immersed in it) and Archimedes’ principle (buoyant force on object in a fluid is equal to weight o fluid displaced by object), using a penny tossed into a water and a penny on an aluminum foil on top of the water as an example of buoyancy. Aside from that experiment, the Koolies also performed a soda-can blowing experiment, showing Bernoulli’s principle (as velocity of fluid increases, pressure exerted by the fluid increases). Blowing in between the two empty cans caused them to be forced together slightly. The Koolies’ carefully thought out experiments and way of explaining was well taken in by me and it was all comprehendible.


Table four, the Cheeseballs, taught lesson 9.3, which was about ways of describing matter, emphasizing their experiment on the physical learning of chemical changes. Vocabulary words they explained include physical property (any characteristic of a material that you can observe without changing substances that make up the material), physical changes (a change in