A. Why can't a pen be used to draw the baseline on the chromatography paper?
B. Why is it important to stop the chromatograph before the solvent reaches the top of the paper?
C. Why is it important to keep the dye spots above the solvent level?
D. Why is it important to mark the solvent level on the chromatography paper when you remove it from the petri dish?
Extra credit and/or extra fun possibilities: Experiment with different solvents such as pure water, rubbing alcohol, or a mixture of alcohol and water. Do not use flammable solvents to experiment! There are often interesting dyes making up the colors of marker pens (especially black). If you want to experiment with marking pens remember not to use permanent ink markers for this experiment.