News

Learning Diffusion: Concentration Required!

Kim Moser’s 7th grade science students recently learned about diffusion and how it relates to a semipermeable cell membrane through an exciting hands-on lab experiment. The question to be answered: How can diffusion be observed?

Students wasted no time in starting their investigation, beginning with constructing their lab. Partners worked together to fill a glass beaker with a water/iodine solution and prepared a baggie with a cornstarch and water mixture. 

Back at their seats, they clipped the cornstarch mix bag to the side of the beaker, submerged it in the iodine solution, and sat back, pencils and lab packets in hand to wait for any change to occur in their materials. 

After some time the students began to see their white cornstarch/water solution turn purple! 

“Which substance has a greater concentration?” Moser asked.“How do we know which has a greater concentration?” and, “What is the evidence that the baggie is semipermeable?”

The students were able to conclude that the iodine diffused through the baggie. “It would be passive transport if it were a cell,” noted Parker Pinson.

What did the students think overall? “It’s interesting to see it change colors,” said Maggie Anderson. They also concluded that it is not a good idea to store iodine in a plastic bag!

Mrs. Moser sure knows how to turn learning about diffusion and transport through a cell membrane into a fun color-changing scientific experiment.

Fish, Pennies, And Teamwork In STEM Class

What do fishing and pennies have to do with science? In Mrs. Ellen Peek’s STEM class, it means a friendly competition that put students' scientific skills and collaborative teamwork to the test.

“Prior to Christmas break we read Luke 5:1-11” explains Peek, “when Jesus asks Simon and the other fishermen to throw their nets out - even though they had worked all night fishing and caught nothing. When they did, they caught so many fish that their nets began to tear and the boats began to sink. For this project, students were challenged to build a boat that could hold the most weight without sinking. The boat could be no higher, longer, or wider than 6 inches and it had to float and then hold weight.” 

Students set to work in groups, constructing vessels that looked like boats, rafts, and, ships. Crowding around Peek, the groups anxiously waited to see if their vessels met the measurement requirements (point deduction if it didn’t) then they counted together as Peek dropped penny after penny (or “fish” after “fish”) onto the project to see how long before it took on water. 

After many cheers (and ughs!) the groups reflected on what worked and what didn't work, as well as what they could do differently next time for a better result.