Petrol changes color when mixed with iodine solution due to covalent bonding.
iodine solution
Iodine tests for complex sugars. Glycogen is a complex sugar and will change dark purple when iodine solution is added (color is irrelevant, all you really need to know is that the change to a specific color signifies a presence of a macro molecule)
The color not change.
there will be change in the color for iodine into blue,black because of the presence of starch in it.
there will be change in the color for iodine into blue,black because of the presence of starch in it.
there will be change in the color for iodine into blue,black because of the presence of starch in it.
there will be change in the color for iodine into blue,black because of the presence of starch in it.
there will be change in the color for iodine into blue,black because of the presence of starch in it.
there will be change in the color for iodine into blue,black because of the presence of starch in it.
their color
Forever! Its a protein and iodine solution test for starch.
Chemical, When something changes in color, it is a sign of a chemical change.