In the first section of this page, you will write a daily summary of that day's class. For example in your chapter 2 blog, your first entry should be titled 9/3/10. You should then write a one or two paragraph summary of that day's lecture, outlining the major points. In the second section, you are required to add two items (link to a website, video, animation, student-created slide show, student-created PowerPoint presentation) and one journal article pertaining to a topic in this chapter. A one-paragraph summary must accompany each item describing the main idea and how it applies to the lecture topic. Please see the PBWorks help guide for assistance embedding video and other items directly in the page. I will also produce a how-to video on using tables to wrap text around items and other useful tips. Please see the syllabus for organization and grading details.
September 8, 2010: In today's lecture we discussed about Hydrogen Bonds and how they are involved in connecting water molecules. Hydrogen Bonds are known to be very weak bonds. Hydrogen bonds can be broken easily if you are dealing with a few of them. When you try to break up Hydrogen Bonds in huge quantities, they stand strong together and are not easily broken as a single Hydrogen bond. We also discussed the "Special Properties of Water". One property that I probably will not be able to forget are the Hydrogen Bonds that it contains. These bonds help water maintain its liquid form over a wide range of temperatures. Another property of water is Surface Tension. This is caused by a cohesive force that is found on some bugs that help them walk across water. Cohesion is also found in stems of plants. This helps them keep stiff and bring up the water against the force of gravity.
Another special property is the Absorption of Heat. Water has the ability to take in heat without evaporating immediately. This is found helpful in areas near large bodies of water. During hot days, the water helps take in the heat and create a comfortable living area. During the nights, the heat that is trapped inside the water is released. One of the most important properties of water is its ability to be a solvent for many chemical reactions. Chemical reactions require a aqueous environment and water happens to be one of the most used solvent in nature as well as our own body. We also briefly talked about cation's and anion's. Cation's are positively charged ions and anion's are negatively charged ions. Then we talked about hydrophobic and hydrophilic molecules. An example of hydrophilic molecules is sugar. Sugar has OH- ions which create an attraction the slightly positively charged hydrogen ions part of the water molecules. Triglycerides are hydrophobic because they have a neutral charge. The reason for this is because the hydrogen atoms are part of a covalent bond and equally share the electrons. Therefore making them a hydrophobic molecule. Towards the end of class, we briefly talked about hydrolysis (the addition of a water molecule to break up a covalent bond) and also mentioned the pH of certain substances. I have to say that when I first saw the equation for getting the pH, I was confused. Then I went home and decided to try it out on my calculator and it worked out fine! Calculator's can really help sometimes : )