Iodine Test for Starch
Iodine Test for Starch is a way to check if a leaf has made food.
Think of it this way
Drop a few drops of iodine into a bowl of water with starch in it. The liquid turns dark purple or black. Clear water with no starch stays orange-brown. The color change shows you which bowl has starch and which does not.
Explaining iodine test for starch by grade level
Plants make their own food from sunlight. That food is called starch. You can drop iodine on a leaf to check. If the leaf turns dark blue, starch is there.