Summer Research Program for Science Teachers
Dean Saghafi-Ezaz
1999
How clean are the laboratory
tables?
Materials:
Tide with Bleach
black light
paper towels
Homework
Finish the summary questions at the end of this exercise.
Teacher's Questions
Motivation : Group students into 4 per group. Place Tide on each group's lab table. Explain to them that the Tide is a bacteria and must be cleaned from the table using the paper towels. The students are not to use water to clean the tables.
Procedure :
Once the students clean the desk (approximately 10-15 minutes),
shut off the lights and walk around to each desk and show the
students, using the black light, that there is still residual
"bacteria" (Tide) on the tables. [5-8 Content Standard B- Properties of matter]
Summary Questions:
1. How could you have prevented bacterial contamination of the
tables?
2. What types of cleaning agents could have been used to eliminate all of the bacteria? [Teaching Standard B- Orchestrate scientific discourse]
3. Why is it essential to wipe down your tables before each class begins and after each class ends?
4. What types of safety clothing should be used at all times in the laboratory? Why?
5. Why should gloves and safety goggles be worn in the lab at all time? [Teaching Standard D- Ensure a safe working environment]
6. Which scientist recommended that hand washing should be done before and after surgery was performed?
[5-8 Content Standard G- History of science]
7. How does one properly wash his or her hands in a science laboratory?