Gabrielle Lurie/Special to the S.F. Examiner
Daria Soofi, left, teaches an outdoors class on composting as part of
Marshall Elementary School’s outside education program.
"Pulling [the plunger] is going to make the balloon change size," Barrios speculated, writing down his prediction on a sheet of paper, where he was also instructed to note observations. The teacher then plugged the end of the syringe with his thumb to prevent air from escaping, and slowly withdrew the nozzle.
Barrios' forecast proved true: The tiny balloon appeared to inflate inside the syringe.
"So you have fewer molecules in a given amount of space that are pushing on the balloon," thus allowing the balloon to expand, Cook-Endres said.
The fun-with-syringes lesson – which included experimenting with mini-marshmallows and M&Ms in the plastic nozzle as well — kicked off one of five teacher development days this school year in which 40 science teachers are helping to develop the SFUSD's next-generation science curriculum that is set to take effect within the next few years.
Read more at SFUSD.edu