Cresols

Title: Blue Light Date: September 14, 2010 Name: Ciar?n McGirr Purpose Hypothesis- If the light wave length is changed then the rate of photosynthesis will slow down Prediction- The blue light will slow down the rate of photosynthesis as evidence by the pH level. Materials Beaker Colored Cellophane Test Tubes Distilled Water Graduated Cylinder Tape Bromothymol Blue Tap Water pH Probe 2 Sprigs of Elodea Thermometer Probe Drinking Straw Fluorescent Lamp Procedure Place 125 mL of distilled water into a test tube Place a straw into the test tube and blow into the tube through the straw for 3 minutes Add 2.5 mL of bromothymol into the beaker Place Elodea into the test tube Use pH probe to test the pH level Place the test tube into 300 mL of water