Summary

In this activity, students will answer questions while watching the video Kill More Germs by Cleaning… Less? from the Ingenious series produced by the American Chemical Society. Each episode investigates a different topic related to how leading-edge chemistry is taking on the world’s most urgent issues to advance everyone’s quality of life and secure our shared future. This episode investigates the chemistry of cleaning. Unfortunately, clean doesn’t last as long as you might think—this video examines how disinfectants work and also how long they last. Scientists share about the next generation of cleaning products, that keep the germ-killing ingredients in place and effective much longer.

Grade Level

High School

Objectives

By the end of this activity, students should be able to:

• Provide a brief overview of how a cleaning project effectively kills a bacteria or virus particle.  
• Explain the difference between a sanitizing product and a disinfecting product.
• Describe how a Next Generation cleaning product differs from current cleaning products.

Chemistry Topics

This activity supports students’ understanding of:

• Molecules and Bonding
• Molecular Structure
• Intermolecular Forces
• Polarity
• Organic Chemistry
• Polymers
• Functional Groups

Time

Teacher Preparation: minimal
Lesson: 10-20 minutes

Materials

• Ingenious Video: Kill More Germs by Cleaning… Less?
• Student Handout
• Computer and projector with volume, or student device to access video

Safety

• No specific safety precautions need to be observed for this activity.

Teacher Notes

• The Ingenious video series spotlights stories from the frontlines of chemistry research and development, where passionate innovators are stepping up to confront problems like pollution, overfishing, sustainability and personal safety.
• This video, Kill More Germs by Cleaning… Less?, investigates the concept of clean, and CLEAN. Even if something looks clean it might still be harboring microbes—many of them harmless, some of them definitely not. With most of the ways that we clean and disinfect—that is, kill germs—the clean doesn’t last as long as you might think. Disinfectants work by attacking bacterial membranes and viral protein coatings, breaking them down so that those germs fall apart and die. But the germaphobes were always right: as soon as a disinfectant dries, and the surface is re-exposed, like if someone touches or (worse) sneezes on it, it needs to be disinfected all over again. The next generation of cleaning products, however, add a trick: they lay down an incredibly thin polymer layer that keeps the germ-killing ingredients in place and effective for 24 hours at a time.
• The running time of this video is about 7 minutes. As it is a short video and it moves quickly, you may want to show it twice, or instruct students to pause the video as needed on their own devices to ensure that they can record answers to all of the questions.
• The student questions/answers are presented in sequential order in the video.
• An answer key has also been provided for teacher reference.
• The final questions are reflection-based and might be helpful in prompting a class discussion after students have a few minutes to answer them independently.
• The AACT classroom resource library offers a wide selection of teaching resources. Below are several select resources that could be used in combination with the topics highlighted in this video.
  • Lab: The Chemistry of Hand Sanitizer and Soap
  • Activity: Designing an Effective Respiratory Cloth Mask
  • Lab: It’s Alive
  • Demonstration: Analyzing Mixtures