Summary
Highlights
Mr. Andersen introduces a photosynthesis lab that can be frustrating if leaf chads don't sink. He outlines the necessary materials: 100ml distilled water, 1g baking soda (carbon dioxide source), organic baby spinach, a hole punch, and a syringe without a needle.
The first step is to punch out leaf chads from spinach, ensuring they are between the veins. When placed in carbon dioxide water, the chads initially float due to air pockets making them buoyant. The goal is to remove this air to make them sink.
To sink the chads, they are loaded into a syringe. Carbon dioxide water is then drawn into the syringe, and air is removed from the top. A vacuum is created by holding a thumb over the syringe opening and pulling the plunger, which removes air from the leaves and replaces it with water, causing the chads to sink.
The sunk chads are transferred to a test beaker. A light source is placed above it. To prevent the light from heating the water and affecting the experiment, a beaker with regular water is placed between the light and the test beaker to act as a heat sink, absorbing the heat.
Potential variables to study include the concentration of baking soda (carbon dioxide), color of light, and water temperature, all of which affect the rate of photosynthesis. As light energy is provided, water within the leaf cells is split, producing oxygen bubbles. These bubbles increase the buoyancy of the leaf chads, causing them to float, which indicates the rate of photosynthesis.