Jim jill robert and kim each run paper chromatography on an unknown aqueous mixture. Jim gets a red band jill gets a yellow band robert gets a green band and kim gets a red band and a blue band. which student had more than one substance dissolved in the water

Chromatography is an analytical method of separating components of the mixture. Particularly, this method uses the paper chromatography. The color indicates the type of substance existing. Each substance is designated to one color only. So, if your paper showed more than one color, it mean that there is more than one component in there. Therefore, Kim's specimen contains more than one component because of the red and blue band.