A chemist started to carry out column chromatography on a Friday afternoon, got to the point at which the two compounds being separated were about three-fourths of the way down the column, and then returned on Monday to find that the compounds came off the column as a mixture. Speculate on the reason for this. The column had not run dry over the weekend. My guess is that the beakers below the column should have been switched. Or, maybe, the polarities of the two compounds were similar. What does everyone else think?