The test tubes were filled with water, and waterweed was added to fill about one third of each tube. Exhaled air, which contains carbon dioxide, was blown through the straw into the water in each tube for 20 seconds. The test tubes were immersed in a bucket of water. They were tightly sealed with their lids, while still being held underwater. The presence of air bubbles inside the test tubes was recorded. The test tubes were labelled as: Sun A, Sun B, Dark A and Dark B. The tubes were placed in indirect sunlight, and the tubes were placed in a ‘Sun’ ‘Dark’ light proof container indoors. Daily observations about the number and size of bubbles in each test tube were recorded. RESULTS Table 1. The Number and Approximate Sizes of Bubbles Noted in Each Test Tube Test Day 0 Day 1 Day 2 Day 3 Day 5 Day 7 tube Dark A 0.5mm - 1 3mm - 1 4mm - 1 4mm - 1 1mm - 1 0.5mm - 6 1mm - 4 0.5mm - 2 0.5mm - 6 Dark B 1mm - 2 2mm - 2 0.5mm - 1 1mm - 3 2mm - 1 2mm - 1 0.5mm - 7 1mm - 2 1mm - ~5 0.5mm - ~8 0.5mm - ~6 Sun A 5mm - 1 1mm - 4 5mm - 1 5mm - 1 7mm - 1 8mm - 1 0.5mm - ~3 1mm - ~7 1mm - ~10 2mm - 1 2mm - 1 0.5mm - ~20 0.5mm - ~20 1mm - 4 0.5mm - ~30 Sun B 2mm - 3 4mm - 1 4mm - 1 5mm - 1 9mm - 1 10mm - 1 0.5mm - 4 1mm - 5 3mm - 1 1mm - ~10 1 mm - 3 1mm - ~8 0.5mm - ~30 0.5mm - ~30 0.5mm - ~20 Table 2. The Approximate Volumea of Gas in Each Test Tube in mm3 Test Day 0 Day 1 Day 2 Day 3 Day 5 Day 7 tube Dark A 0 0 0.07 14.79 33.9 36
The test tubes were filled with water, and waterweed was added to fill about one third of each tube. Exhaled air, which contains carbon dioxide, was blown through the straw into the water in each tube for 20 seconds. The test tubes were immersed in a bucket of water. They were tightly sealed with their lids, while still being held underwater. The presence of air bubbles inside the test tubes was recorded. The test tubes were labelled as: Sun A, Sun B, Dark A and Dark B. The ‘Sun’ tubes were placed in indirect sunlight, and the ‘Dark’ tubes were placed in a light proof container indoors. Daily observations about the number and size of bubbles in each test tube were recorded. RESULTS Table 1. The Number and Approximate Sizes of Bubbles Noted in Each Test Tube Test tube Day 0 Day 1 Day 2 Day 3 Day 5 Day 7 Dark A 0.5mm - 1 3mm - 1 1mm - 1 0.5mm - 2 4mm - 1 0.5mm - 6 4mm - 1 1mm - 4 0.5mm - 6 Dark B 1mm - 2 2mm - 2 0.5mm - 1 1mm - 3 0.5mm - 7 2mm - 1 1mm - 2 0.5mm - ~8 2mm - 1 1mm - ~5 0.5mm - ~6 Sun A 5mm - 1 1mm - 4 0.5mm - ~3 5mm - 1 1mm - ~7 5mm - 1 1mm - ~10 0.5mm - ~20 7mm - 1 2mm - 1 0.5mm - ~20 8mm - 1 2mm - 1 1mm - 4 0.5mm - ~30 Sun B 2mm - 3 4mm - 1 0.5mm - 4 4mm - 1 1mm - 5 5mm - 1 3mm - 1 1mm - ~8 0.5mm - ~20 9mm - 1 1mm - ~10 0.5mm - ~30 10mm - 1 1 mm - 3 0.5mm - ~30 Table 2. The Approximate Volumea of Gas in Each Test Tube in mm3 Test tube Day 0 Day 1 Day 2 Day 3 Day 5 Day 7 Dark A 0 0 0.07 14.79 33.9 36