Thursday, September 27, 2007
Thurs-Day 1
Bio- we continued our discussion of basic chemistry by illustrating the model of an atom and knowing the characteristics of its components. We defined the term isotope and drew C-12, C-13, and C-14 to note the similarities and differences among these carbon isotopes.
We then returned to bonding between atoms that make up a molecule noting that atoms of a given element are more stable when they have 8 (the OCHO) valence electrons. We noted that covalently bonded compounds, such as H2O, are called molecules. We then looked at the very different type of bonding between positively charged metal ions and negatively charged non-metal ions, called ionic bonding. Substances that are ionically bonded are called salts.
We then looked at a video/animation of solution formation; when salt or any soluble substance dissolves in water, an aqueous solution forms. Picturing solution formation is important in understanding that the aqueous cytoplasm of all cells has many substances dissolved in it.
The video and PowerPoint from today are on Blackboard.
We then reviewed some of our test, noting the careless lack of underlining key terms that I had suggested and noting that, with some care and other test-taking skills (such as writing key information directly on your test at the very beginning so that you have that reference throughout the exam), many more points can be earned on your next exam. The major key is that you show care; this attention to detail automatically prevents many of the common errors that were made on this exam.
Chem 7- There is a matter and separation techniques powerpoint on Blackboard; check it out.
We further discussed types of potential and kinetic energy as well as the three modes of kinetic energy: translational, rotational, and vibrational. We then discussed the units of energy. We saw that TEMPERATURE is NOT ENERGY but rather a MEASUREMENT of the AVERAGE kinetic energy of the particles that make up a given sample of matter.
We discussed some of the formulas on the lab write-ups. The THREE labs are due tomorrow: Lab Equipment, Measurement/Density, and Separation of a Sand/Salt Mixture. Make sure that they are PERFECTLY clear, neat, and organized and that ALL UNITS are clearly written in all calculations.
Chem 8/9- We discussed some of the formulas on the lab write-ups. The THREE labs are due tomorrow: Lab Equipment, Measurement/Density, and Separation of a Sand/Salt Mixture. Make sure that they are PERFECTLY clear, neat, and organized and that ALL UNITS are clearly written in all calculations.
We finished discussing all of the separation techniques and the physical properties that are exploited by these techniques. The PowerPoint from today is on Blackboard. We also viewed an animation that shows the formation of an aqueous solution of a salt.
We demonstrated a couple of intense chemical changes:
the reaction of sucrose with sulfuric acid to form pure black carbon, water vapor, and some sulfur dioxide fumes (in the hood! SO2 is very harsh on the lungs if it were breathed). We also started to melt sucrose (physical change) but then we saw it decompose into black carbon and water vapor (chemical change).
We then returned to bonding between atoms that make up a molecule noting that atoms of a given element are more stable when they have 8 (the OCHO) valence electrons. We noted that covalently bonded compounds, such as H2O, are called molecules. We then looked at the very different type of bonding between positively charged metal ions and negatively charged non-metal ions, called ionic bonding. Substances that are ionically bonded are called salts.
We then looked at a video/animation of solution formation; when salt or any soluble substance dissolves in water, an aqueous solution forms. Picturing solution formation is important in understanding that the aqueous cytoplasm of all cells has many substances dissolved in it.
The video and PowerPoint from today are on Blackboard.
We then reviewed some of our test, noting the careless lack of underlining key terms that I had suggested and noting that, with some care and other test-taking skills (such as writing key information directly on your test at the very beginning so that you have that reference throughout the exam), many more points can be earned on your next exam. The major key is that you show care; this attention to detail automatically prevents many of the common errors that were made on this exam.
Chem 7- There is a matter and separation techniques powerpoint on Blackboard; check it out.
We further discussed types of potential and kinetic energy as well as the three modes of kinetic energy: translational, rotational, and vibrational. We then discussed the units of energy. We saw that TEMPERATURE is NOT ENERGY but rather a MEASUREMENT of the AVERAGE kinetic energy of the particles that make up a given sample of matter.
We discussed some of the formulas on the lab write-ups. The THREE labs are due tomorrow: Lab Equipment, Measurement/Density, and Separation of a Sand/Salt Mixture. Make sure that they are PERFECTLY clear, neat, and organized and that ALL UNITS are clearly written in all calculations.
Chem 8/9- We discussed some of the formulas on the lab write-ups. The THREE labs are due tomorrow: Lab Equipment, Measurement/Density, and Separation of a Sand/Salt Mixture. Make sure that they are PERFECTLY clear, neat, and organized and that ALL UNITS are clearly written in all calculations.
We finished discussing all of the separation techniques and the physical properties that are exploited by these techniques. The PowerPoint from today is on Blackboard. We also viewed an animation that shows the formation of an aqueous solution of a salt.
We demonstrated a couple of intense chemical changes:
the reaction of sucrose with sulfuric acid to form pure black carbon, water vapor, and some sulfur dioxide fumes (in the hood! SO2 is very harsh on the lungs if it were breathed). We also started to melt sucrose (physical change) but then we saw it decompose into black carbon and water vapor (chemical change).
# posted by C @ 2:00 PM 
