When we mixed the water and salt together, we noticed adhesion. The salt clumped to the water and preferred the water to a dry surface such as skin. It was evident that hydrogen bonds are stronger together when we tested the different ratios of salt to water. We started out testing a ratio of more salt than water and realized that the salt did not dissolve as easily. However, with more water the salt grains dissolved quicker. The salt grains became smaller which shows how water is an effective solvent. With the rope, we noticed that the water was strong enough to break the rope’s material. It separated the fibers of the rope. The fibers reminded us about the root hairs that we learned about in lecture. The rope has to overcome the surface tension in order to absorb the water. Through mass flow, the water molecules worked collectively, it was able to move through the rope. The last material we used was clay. From lecture, we learned that liquid water is more dense than solid water. We submerged a piece of clay in water and noted that the material began to break down. When we poured water over a larger piece of clay, we noticed that the water just rolled off, the clay didn't absorb the water much. The clay also changed its form. The clay became softer and more flexible.
In this water exercise, our group divvied up the materials to experiment on. Half of us tested the effects of water on a sponge, dishwashing pad, and sand. The water absorbed fairly quickly by the sponge. This displayed an excellent example of adhesion. Water didn't change the properties of the sponge, but it definitely dampened it. If one were the squeeze the sponge, all of the absorbed water would spill out. When water was added to the dishwashing pad, there was good adhesion and cohesion that was displayed. The water stuck to the pad as well as to itself. We could see some surface tension through the pores as well. When we poured water onto the pad, a lot of the water "fell off", showing some mass flow. Finally, the sand also displayed cohesion and adhesion by the water. To the touch, the sand went from a grainy solid to a mushy liquid, despite the properties of the sand not being changed. That is the beauty of water!
Once again we noticed the power of play.We manipulate and played around with the different materials given to us. We were able to see just how strong water is and the different things it is able to do. It goes beyond just playing around with material but connects to science because we were looking for something specific. We were observing the way water worked and jotting down what we thought. For those experiment is was definitely better to work with a partner rather than alone. A partner is capable of seeing something that you may have missed. Working together, we were able to take our notes from lecture, apply them to the lab today, and deepen our knowledge of water and its properties.
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