Tip 5.18.3.
Abstracts are challenging! Write yours at the end of the writing process when you have a clear idea of what ideas are most important to communicate.
Plants adapt to environmental fluctuations by changing how they manage energy. Photosynthesis occurs in plants as both light-dependent and light-independent reactions. Chlorophylls within plant cells are responsible for harnessing light energy and water in order to create oxygen, ATP, and NADPH. This experiment studied the effect of various light intensities on oxygen gas production as a measure of photosynthetic activity, in order to see if the oxygen production rate increased with available light energy. Samples of Elodea canadensis were dark adapted and oxygen production was measured at various light intensities (0, 10, 30, 50, 80, 140, 200, and 380 \(\mu\text{mol photons m}^{-2}\text{s}^{-1}\)). The average rate of change in dissolved oxygen for 0 \(\mu\text{mol photons m}^{-2}\text{s}^{-1}\) was -0.162 0.154 mg/L,hr due to the intake of oxygen through cellular respiration. Elodea canadensis shows the most efficient use of light energy for \(\text{O}_2\) production at 80 \(\mu\text{mol photons m}^{-2}\text{s}^{-1}\) and plateaued around 0.9 mg/L/hr for any higher light intensity. This suggests that photosynthetic activity can only perform efficiently at certain light intensities, confirming trends from research with photosynthetic algae. Further research should investigate the limiting factors on photosynthetic activity and evolutionary drivers and discrepancies between organisms.
Gasses can be impossible to identify visually, but their other physical characteristics, like flammability, smell, and molar mass, are well documented. The objective of this experiment was to determine the identity of three unknown gasses. Molar mass was determined using the ideal gas law, PV = nRT, and a container of known volume. Flammability was determined using flame tests. Similar gasses were distinguished using a limewater test. Based on a molar mass of 39.97601g/mol, lack of flammability, and formation of a precipitate in a limewater test, unknown gas one was determined to be \(\text{CO}_2\text{.}\) Based on a molar mass of 35.9581g/mol and lack of flammability or a precipitate in a limewater test, unknown gas 2 was determined to be Ar. Based on an experimental molar mass of 42.5765g/mol and a positive flame test, unknown gas 3 was determined to be \(\text{C}_3\text{H}_{8(g)}\text{.}\)