Mike Samale’s 15 students each had their supplies for the lab from home: a small piece of soap (any kind), a cup of water and paper towel.
They all held their soaps up for their Zoom cameras and shared what kind of soap they had. Mr. Samale noted that he had Ivory soap. Watching Mr. Samale, who was wearing a black shirt as a background so they could more easily see what he was doing over Zoom, they followed his lead and placed their soap in the water.
There was a chorus of “Mine doesn’t float!”
They were quick to notice that his was the only soap that was floating, so he asked for suggestions about why his soap floated and theirs didn’t.
“Could it be the water?”
Following his directions to remove their soap from the water and place it on the paper towel, the next task was to Google “Why does Ivory soap float?” (“I’ve never heard of Ivory soap!”). They quickly reported that it’s whipped with air in production, so their theory became, “The air helps it float.”
The next task: Google the main ingredients in most soaps. Students’ incredulous voices filtered back: “Vegetable oil?” “Olive oil?” “Animal fat?!?” and a tentative “Sodium laurel sulfate?”
Mr. Samale asked, “Do any of those ingredients sound like they would have air in them?” In the resulting conversation, students agreed that they probably do, and suggested another ingredient used was water, which helped build consensus around air being the key to Ivory soap floating.
He continued, “If air is a gas, what can we do to the air in your soap to make it float?” “How do we get gas from water?”
“Burn it!” was one enthusiastic response.
“What device do we use that could mimic heat?” he asked.
Giving precise instructions for students to carefully place their soap on a paper towel or plate, he directed the students to microwave their soap pieces for 25 seconds, and to be careful in removing the soap, since it would be very hot.
As students returned from their trip to the microwave, there were exclamations of “My soap looks so weird now!” “Mine looks like a piece of cotton!” “Oh yeah, that’s awesome!” “It smells kind of weird.”
The microwaved soap pieces went back into the water – and they floated. (For the couple that didn’t, those soaps got another 20 seconds in the microwave.) Observations poured in over Zoom. “The water around it is bubbling!” “I can feel the air molecules when I squeeze it in the water.” “It’s still floating!” “Now it’s flat!” “Can you use this soap in real life?” “This is actually cool!”
When asked for a show of hands from those whose soap was now floating, all 15 squares in the Zoom gallery had a hand waving.
“What process did we just do?” asked Mr. Samale.
“Well, we had an educated guess,” said one.
“Then we tested it,” said another.
“The scientific method!” the students said in unison.