Color Separation Activity
Take a page of newspaper and cut off the top or bottom
margins—don't cut anything with type on it. The strips of
paper should be about an inch wide and about six inches long. Fold
the strips in half, lengthwise.
Next, pour two tablespoons of water into a glass, followed by two
tablespoons of rubbing alcohol. Stir them together.
In a spoon, mix some drops of blue and red food coloring together
until you have dark purple.
Now back to your paper strips. Dip a paintbrush, or toothpick,
into the spoon, and paint a thin stripe of purple on one of the
paper strips. The stripe of purple should be about 2 inches from
one end. One a second paper strip, paint a thin stripe of green
food coloring. Take the green food coloring straight from the
container, and don't mix it with any other color.
Drape your paper strips over the side of the glass. The strips of
paper should be positioned so that the stripes of purple and green
are just above the liquid. Tape the far end of the paper strips to
the side of the glass so they stay in place. Let everything sit
for 20 minutes.
Note: You can do this same experiment using water-based
color markers instead of using food coloring. We suggest you use a
black marker on one strip, and a green marker on the second strip.
You can also use a coffee filter instead of newspaper strips.
Twist one end of the filter and let that be the end that sits in
the water-alcohol mixture. Paint your stripe of color just above
where the twist begins to unfold.
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