Homework 9/18/2007

1. Readings

How do we know atoms exist?, and How do we know here are electrons and protons? http://dev.nsta.org/ssc/pdf/v4-0962s.pdf

Carbon Three Ways: http://www.nyu.edu/pages/mathmol/txtbk2/topic5.htm

Carbon Compounds: http://www.nyu.edu/pages/mathmol/txtbk2/topic6.htm

Water and Ice: http://www.nyu.edu/pages/mathmol/txtbk2/topic7.htm

Water and Ice II: http://www.nyu.edu/pages/mathmol/txtbk2/topic8.htm

2. Online Activities

Go to http://www.biology.arizona.edu/biochemistry/biochemistry.html

Complete the sections labeled "Chemistry" and "Acids and Bases"

3. Create your own pH indicator

Materials

Red cabbage

Isopropy alcohol (rubbing alcohol)

Disposable food storage container

Procedure

Shred 1/4 to 1/2 of cabbage as you would for cole slaw

Place the cabbage in a disposabe food storage container and cover the cabbage with the rubbing alcohol (caution, alcohol is flammable)

Cover and allow to stand overnight

Romove the cabbage from the mixture and keep the liquid. The alcohol should now be a deep red color. Dispose of the cabbage in the trash.

Save the liquid for the next lab exericse. The liquid can be used as a pH indicator and should turn a deeper red when an acid is added and green when a base is added.

When finished with the cabbage solution you can dispose of it down the drain. Dispose of the container or pass through a dishwasher before using again

4. Acid/Base lab

See handout

All materials are available at School Box (or other school supply store)

Household items may be substitued for some items

Small glasses (aoubt the size of a shot glass) may be substitued for the 30-ml beakers.

Plastic ware may be used instead stirring rods

Record exact materials used in your lab book

In addition to using the pH paper, try using the cabbage solution prepared earlier. Record observations when using the cabbage solution. Two suggestions for using the cabbage solution are 1. Place a drop of the solution on a paper towel and place a drop of the substance to be tested on the same spot. Note if there is any color change. 2. Place a few drops of liquid in a small glass or test tube, add a substace to be tested on drop at a time and note any color change.

5. Just for your information, here is link to a periodic table that gives informatin about each element

http://www.chemicool.com/

Here is an on-line biology book that contains a great deal of information, I highly recommend reading the section corresponding to each weeks classroom topic

http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookTOC.html