Answer:
B. Cornstarch
Step-by-step explanation:
Iodine reacts with some substances and changes color as a result of the reaction. Out of the items listed:
B. Cornstarch will react with iodine and produce a blue-black color. This reaction is due to the presence of starch, which reacts with iodine to form a complex molecule called iodine starch.
A. Baking soda, also known as sodium bicarbonate, does not react with iodine and will not cause a color change.
C. Salt, also known as sodium chloride, does not react with iodine and will not cause a color change.
D. Powdered sugar, also known as sucrose, does not react with iodine and will not cause a color change.