Kia Ora koutou,
please check out our "The science of Art - Journal" pages on all the students blogs. This space has been created so we can share our Science investigations with you....
Check out our first investigation......
Color Changing Milk
- Pour enough milk in the dinner plate to completely cover the bottom to the depth of about 1/4 inch. Allow the milk to settle.
- Add one drop of each of the colours of food colouring to the milk. Keep the drops close together in the center of the plate of milk.
- Find a clean cotton swab for the next part of the experiment. Predict what will happen when you touch the tip of the cotton swab to the center of the milk. It's important not to stir the mix. Just touch it with the tip of the cotton swab. Go ahead and try it.
- I wonder what will happen when... I place a drop of liquid dish soap on the other end of the cotton bud. Place the soapy end of the cotton bud back in the middle of the milk and hold it there for 10 to 15 seconds.
- I wonder what will happen when... I add another drop of soap to the tip of the cotton swab and try it again.
- Experiment with placing the cotton swab at different places in the milk. Notice that the colors in the milk continue to move even when the cotton swab is removed. What makes the food coloring in the milk move?
This is what I changed...
- Repeat the experiment using water in place of milk. Will you get the same eruption of color? Why or why not?
- What kind of milk produces the best swirling of color: trim, whole milk, cream? Does the fat content of the milk affect the reaction?
The dish soap must remain the same in the experiment. Use the same brand for each trial and the same amount of soap. Use the same colors and the same amount of food coloring in each trial. Pour the same amount of liquid into the bottom of the dish. All of these steps ensure that you have standardized the conditions as much as possible and have isolated a variable--the one thing that changes in the experiment. In this case, the variable is the type of milk you are using. Take photos of the reactions (maybe even videotape the reactions) to document your discoveries and share at the science fair.