Chemical Changes and Healthy Bodies all from Snot!

Jean K. Fairchild, GFW Elementary School, Gibbon, MN, based on an original activity from thinkquest.org, Boogers and Snot.
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Summary

In this demonstration, students observe the properties of "snot"; determine any changes within the "snot"; record and discuss their findings. This demonstration is done within a unit on the respiratory system. It leads to lively discussions about the importance of snot and what we can learn from snot.

Learning Goals

This activity is designed for students to observe the properties of the "snot", predict what will happen when matter is added, explain the purpose of snot, and understand the importance of snot in a healthy body.

Key concepts learned from this demonstration are snot has an important job in keeping our bodies healthy and snot changes when we are ill.

Vocabulary words discussed: mucus, snot, boogers.

Context for Use

Grade level elementary- junior high. Demonstration done by the teacher but could be done in small groups. Students should already have observation and note taking skills. If this is done after a unit on physical and chemical changes, that should be reviewed in the discussion. This demonstration can easily be modified.

Description and Teaching Materials

Review the parts of the respiratory system. Why during the cold and flu season do we talk the need to cover your mouth, wash your hands and throw away used tissues? How can we tell we have a cold? Students will volunteer answers dealing with snot, runny noses and coughing. This demonstration makes "snot."
I used chalk dust for the boogers and stressed the chemical change made when the corn syrup was added to the gelatin. The reaction from the students is terrific. They are grossed out yet curious and eager to share their knowledge.

Teaching Notes and Tips

Do not let the gelatin set more than five minutes before stirring it. Stir it after two or three minutes. Remove the fork after stirring or the gelatin will glop to it and be very hard to remove. The "snot" will set within 10 minutes or so after adding the corn syrup so if you leave it between classes, you will have to dig to the bottom to get any strands. The "snot" should be thrown into the garbage and not put down the drain or disposal.

Students will want to make this at home.

I first used this demonstration because it was fun and gross. The students were eager to watch and share stories. I now stress the chemistry, changes and health signs that are involved with snot. The question about the color of snot (yellow or green or clear) as an indicator of an infection is still being debated but most people say that green snot equals a doctor's visit.

Assessment

Students would be asked to turn in their notes of the demonstration along with a list of ways to keep healthy. Notes would be scores to the set class requirements. There would be no test. The class would be praised for good health habit (coughing into their shoulders, washing hands after sneezing, throwing away tissues, etc) and reminded to continue to use those habits.

Standards

Grade 4 Life Science 4.4.4.2.1 Recognize that the body has defense systems against germs, including tears, saliva, skin and blood.