ScienceMakers Toolkit Manual - The History Makers

Chemistry
Instructions:
1. Put cabbage in cooking pot and cover with cold water. Cook over medium-high heat until the water
turns a deep purple-red.
2. Allow to cool. Pour liquid into jar. (The cabbage liquid can be kept in the refrigerator for several days.)
3. Pour equal amounts of liquid into each of the glasses.
4. One at a time, try adding a small amount of the materials for testing to each of the glasses.
5. Notice what happens in each glass.
6. Have the students classify the acids and bases based on common traits (can we eat them, what are
they used for, etc.)
Possible Interactive Questions:
What’s Going On?
The red cabbage indicator turns pink when there is an acid in it, and blue-green when there is a base in it. The
indicator remains reddish-purple when there is a neutral substance in it.
pH is a measure of a substance’s chemical ability to take or give hydrogen ions. Commonly, we classify substances
as acids (will take hydrogen ions), bases (will give hydrogen ions), or neutrals (not willing to give or
take).
What does this have to do with agriculture? One of a farmer’s many jobs is being a scientist. To ensure good
crops, a farmer must test the soil to make sure it is at the right pH and also to check for nutrients needed by the
plants.
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Isiah M. Warner - Video Clip Transcription
Clip 1 - Family Stories: My grandmother used to tell me stories about slavery…She would tell me for example
about her great-grandfather, sorry, her grandfather, would be my great-great grandfather, who was, apparently a
medicine man from Africa. And, she would tell me a story about how he had all these different medicines, and
there would be people from all over who would come to get treated for medicine. In those days, there weren’t
any cures for cancer. So, whites and blacks would come to him to be treated. So, it wasn’t just like it was restricted
to blacks. She would tell me stories about whites and blacks who would come to him. In fact, when I go
back to Africa, there’s a lot of truth to the herbalists in that they work alongside the traditional medical doctors
nowadays. And Africans really believe in the herbalists, and it turns out a lot of the medicinal medicine we get
from plants come from herbs in countries like Africa, South America, and that’s usually some medical basis
behind the use of these compounds. As a matter of fact, one of my research areas is I’m extracting some compounds
that are now used in Africa for treating patients, and we’re trying to fi nd out what are the chemicals in
there that might be helping.
Clip 2 - Favorite Subjects: I always liked science and mathematics. Early on, you know, I went back and
looked at my grades, they were terrible when I was in fi rst grade. Again, probably because of my emotional
attachment to my mother, you know, I was very emotionally attached to my mother, didn’t want to be away
from her, which is part of the reason why they had to escort me to school. My grades were terrible, but as I
progressed it was clear to everyone that I was the student in the class and I graduated valedictorian of my class
eventually.