Now that you've gone over the procedure for preparing dilutions, decide on what solutions you want to prepare for your calibration curve. You will need to determine the final concentration of atrazine stock solution you would like to use for your calibration curve, and the corresponding initial volumes of stock solution. For this remote-learning activity, you may choose anywhere from 0.050 mL to 1.000 mL as your initial volume (see buttons below), which is then diluted to a total volume of 2.000 mL before the spectrum is measured. You may assume the volumes shown are the ones used for the dilutions when calculating the diluted atrazine concentration. Once you've picked an initial volume, inspect the Excel or .csv files carefully. There are two peaks that commonly appear near 220 nm, one at ~215 nm and one near ~224 nm. Your calibration curve should be based on the peak closer to 224 nm. When you are finished collecting your data, use the button at the very bottom to navigate to part 2.