Chemistry had the longest class time dedicated to the measurement lab. This lab can be tough. For example, the students have to figure out how thick a piece of aluminum foil is. I only told them that the density of aluminum is 2.7 grams per milliliter. So how do you do it? First, make sure the foil is either a square or rectangle and measure its length and width. Make sure you measure in centimeters! Then find the mass of the piece of foil. OK, Now take the mass you found and divide it by the density. You will see masses are cancelled and you are left with volume of the piece of foil. Now take that volume and divide it by the 2 dimensions you already found (length and width) and that will give you the third dimension, thickness of the foil. Hurray!!
AP Biology began Activity C in the Osmosis and Diffusion Lab. We took potato sections and immersed them in different concentrations of sucrose solution. Some of these potato sections will lose weight while others will gain weight. This depends upon the concentration of the sucrose solution. We will analyze data tomorrow to determine the concentration of the sucrose inside the potato cells.
I also began the second lecture of the year. Water and its behavior was the star. Now everyone should know why you can skip a stone across the surface of a pond.