The release of O₂( oxygen) from the process of photosynthesis is what made them to be able to float.
<h3>What is Photosynthesis?</h3>
This is referred to as the process in which green plants manufacture their food in the presence of sunlight which is trapped by chlorophyll.They are known as primary producers and they use compounds such as water and carbondioxide.
The reactants mentioned above undergo series of reactions which leads to the production of glucose and oxygen is given off as a result which is the element responsible for the floating of the aspirated spinach leaf disks in this scenario.
We can collect a sample of that food and add a drop of blue litmus solution. If the color of the litmus solution changes to red, it contains an acid as one of its ingredients.