More rAinboW science: Milky
rAinboWs
You'll need:
• Whole milk (enough to cover bottom of cookie
sheet or shallow flat bottom saucer)
• a few different colors of food colouring
• dish detergent
• a cookie tray or flat bottom dish
• popsicle sticks or q-tips or small paint brush
To start, pour some milk into a cookie tray or dish
(just enough to cover the bottom) and add a few
drops of food coloring throughout.
Dip the sticks, q-tips or paint brush in the soap and
then into the milk.
Watch as the milk "runs" away from the detergent in
mini-explosions/rainbows!
the science: This movement happens as the
fat from the milk reacts with the soap. The food
coloring makes it possible for us to see this chemical
reaction.
Why did the dish soap make the milk swirl?
When the dish soap liquid is added to the milk, it
reduces the milk's surface tension. The food coloring
and water in the milk gets pulled away from the fat
particles. This results in a colorful swirling motion.
sources: Gosciencegirls.com,
Incrediblescience.com
officialKidsMag.com • August 2020 • 45
