Small disks were cut from spinach leaves that had been treated to remove any air from inside the leaf. The disks were placed in a solution that allowed them to carry out photosynthesis. At first, all the disks sank to the bottom of the
container. These disks were then used for two different investigations.
Investigation 1
The disks were divided into five groups. Each group was exposed to light of a different intensity, measured in watts
per meter squared (W/m2). Some of the disks began to float. The results of the first investigation are shown in the
graph below.

State the relationship between increasing light intensity and the percentage of disks floating at the conclusion of
Investigation 1.