A breath of science reveals clues about photosynthesis

Students in Mrs. Glavan's 8th-grade Science class have been studying how matter and energy flow through systems. 

This week, students performed a lab to see what happens when we exhale into bromothymol blue, which is a pH indicator. The color changes from blue to yellow when infused with our exhaled CO2.

Then, students designed an experiment with the solution and a common water plant, elodea, to see how it reacts in the presence and absence of light (covered in tin foil). 

There were “ah-ha!” moments when they saw the solution with the plant, which was exposed to light, turn back to dark blue, whereas the solution with the plant in the dark stayed yellow. This was evidence that photosynthesis occurs in the presence of light.