BioEd Online

Teacher Background

The Science

Remember that this activity “models” how water droplets travel. In real life, Coronavirus (SARS-CoV-2) spreads mainly through person-to-person contact—especially through very fine droplets and particles released into the air when a person with the infection coughs, sneezes, sings or talks. These droplets can land in the mouths or noses of other people nearby and possibly be inhaled into the lungs. The virus also is believed to spread through contact with contaminated surfaces or tiny droplets or particles that linger in the air as aerosols. The greatest risk of spreading the virus occurs when people are close together (within about six feet). A person with SARS-CoV-2 infection can develop the illness known as COVID-19.

Objectives and Standards

Students will describe the distance traveled by water droplets and explain how their findings demonstrate the importance of physical distancing to prevent transmission of infectious diseases by respiratory droplets, such as with COVID-19.

 

Science/Health/Math Skills

Observing

Comparing

Measuring

Interpreting

 

NGSS Science & Engineering Practices

Asking questions and defining problems

Developing and using models

Planning and carrying our investigations

 

Materials and Setup

Can Drop Travel in Air slide deck to project during

Each student will need the following items.

• Small mirror
• Water (small amount to create water droplets and additional water to explore how far droplets travel)
• Spoon
• Large plastic cup or container (large enough for students to submerge an entire hand)
• Wall or wooden fence outdoors
• Ruler, yardstick or measuring tape
• 3 sheets of blank paper (8¹/₂ x 11 inch)
• Tape
• Science notebook or additional paper for recording observations

 

Procedure and Extensions

Engage

1. Ask students, Have you ever been near someone when they sneezed? What happened? [Responses may vary, but someone may say that they felt the force of the sneeze or even got wet! Accept all answers.]

2. Explain that they may have felt droplets of saliva and mucus that were projected into the air when the person sneezed. Yuk! Point out that saliva and mucus from the mouth and nose mostly consist of water.

3. Follow by asking, Have you ever looked closely at a water drop? Direct students to use the spoon to place a small amount of water onto the surface of the mirror, creating one or more droplets.

4. Tell students to observe the drop(s) carefully, draw one drop in their science notebooks, and write three words describing the appearance of the drop.

 

Explore

5.   Refer to the student activity description and sheet, Investigating Droplets. You may have students do Part 1 together with you (the teacher) if they are participating with you outdoors or online at home. They will need to have a mirror handy. (Note: During the COVID-19 pandemic, it is not advisable that students remove their masks in the classroom to breathe on a mirror.)

6.   If possible, have each student breathe onto the mirror. Ask, What do you see on the surface of the mirror? If not mentioned by students, point out that the fog on the mirror consists of tiny water droplets, smaller but similar to the ones they observed. Follow by asking, How far do you think these water drops might be able to travel in the air?

7.   Part 2 must be conducted outside, either at school with your supervision or at home, with students working with an older child or adult. Students will write their observations to share in class.

8.   Read the instructions together.

 

Explain

9.   Have students share their recorded observations of numbers of drops at each distance: 1 foot, 3 feet and 6 feet. If possible, create a class graph that includes each student’s counts. Have students calculate the average number of drops counted for each distance.

 

 

10.Ask, What does this information tell us about how far water droplets, which are large enough to see, can travel in the air? Students should be able to conclude that fewer drops of this size are able to travel as far as six feet.

11.Follow by asking, How can we use this information to help us keep one another healthy? Use the accompanying slides to guide a discussion with the class.

1. Cough and sneeze into a disposable tissue or your elbow (demonstrate). Then wash your hands!

2. When around others during the COVID-19 pandemic, wear a mask that covers your nose and mouth.

3. Stay at least six feet away from people who are not part of your household, and avoid large gatherings.

12.If not mentioned by students, conclude by pointing out that scientists know droplets can enter another person through their mouth, nose and eyes. Droplets also can be breathed in or land on something that someone else touches afterward. This is how many microbes that cause illness and disease can be spread. During the COVID-19 pandemic, we must be extra careful not to spread the virus or catch it from someone else.
 

Evaluate and Extend

14. Watch one of the following videos with your students. Have each student write three ways they are going to protect themselves and keep others around them healthy.
 

Cover Coughs and Sneezes (younger students)
Centers for Disease Control and Prevention
https://www.youtube.com/watch?v=mQINuSTP1jI

 

COVID-19 Stop the Spread of Germs (older students)
Centers for Disease Control and Prevention
https://www.youtube.com/watch?v=kEhNyxKopsg

 

Handouts and Downloads