Monday, September 13

We started class today with Mr. Henderson telling us to get out our calculators, lab notebooks, packet, and to make sure we had patience. We began class by reviewing Lab MM6, the Conservation of Mass Lab. During this lab, we measured the mass of chemicals before and after a chemical reaction. The purpose was to figure out if mass was retained or changed during a chemical change. One person from each lab group went to the front of the room to record their data so we could see what the overall data of the entire class was. This is what the class data turned out be:

We then discussed whether or not the results of the lab shows that mass is retained during a chemical change. Some people said that mass was lost, since some of the masses decreased lightly. Others said that the mass stayed the same because it only changed slightly. Mr. Henderson told us that the mass had stayed the same. He said that in chemistry, 157.37=157.21. This could be because of the uncertainty or some of the chemicals may have fallen out when it was measured for the second time.

Once we finished reviewing the lab, we started to learn about metric conversions. We were told we had to memorize four of the prefixes. We learned a great way to remember them.

1 kilometer=1000 meter

100 centimeters= 1 meter

1000 millimeters=1 meter

10^9 (1,000,000,000) nanometers=1 meter

We also learned a way to remember the many different prefixes by using a scale.

We learened how to use this scale to do metric conversions. If you wanted to convert a kilometer to a meter, you move the decimal place 3 places to the right since the base unit is 3 spaces to the right of the kilo. If you wanted to convert millimeters to meters, you move the decimal place 3 places to the left since the base unit is 3 units to the left of the milli. We practiced doing this by doing a worksheet, page 7 in the packet.

We then went over problems 7 and 8 form the worksheet. 7 was converting 1 mL to kL. First we learned to convert it to L. If you move the decimal place 3 to the left, you get 0.001 L. If you move that 3 more places to the left, you get 0.000001 kL. for 8, the problem was to convert 1.0 Mg to mg. Mg was not on the scale, but it was listed on the worksheet as 10^6. If you calculate 1.0 X 10^6, you get 1,000,000 g. It still needs to be put into mg from g, so you move the decimal place 3 spaces to the right. The solution to that is 1,000,000,000 mg (10^9 mg).

We finished class by being assigned our homework to do a Webassign reading sheet for tomorrow and our Delicious Assignment, which is due on Friday. Overall, it was a very productive class.