Teacher Instructions

Color Mystery

Age Group: Grades K-4

Elisabeth Russell

1/14/08

The objective of this experiment is to broaden the understanding of what makes up color. The key concept of the experiment is to show how colors are made up of other colors. The use of the black markers will show how the color black is simply the mixture of different colors. Also, the optional coloring at the end of class will allow the students a hand-on experience of the results of mixing various colors together.

The usage of three different black markers in the experiment is to demonstrate that black can be made by mixing different colors and different companies make their black markers using different colors resulting in a difference in results when the black color is broken down using water.

Chromatography: a method used to separate mixtures because of intrinsic differences in absorbency

Materials List

3 different types of washable black markers per group (you can substitute one marker with a permanent marker to show that it is not water soluble)

Purple Skittles

Coffee filters

Chromatography paper (coffee filters work as well)

Styrofoam/plastic plates

Plastic cups

Water-soluble multi-colored markers (for the optional hands on coloring if time allows)

Paper (for the optional hands on coloring if time allows)

Water

o (Can be prepared beforehand) The “evidence” can be prepared before class using one of the three black markers. The paper should be cut into small strips (1 inch wide, 3-4 inches long). The different types of markers should be labeled #1-3 (e.g. permanent markers #1, type A water soluble marker #2, type B water soluble marker #3).

Procedure

Demo: Place a purple skittle onto a coffee filter and onto of a plate

Put droplets of water on top of the skittle allowing the candy to absorb the water

Add enough water droplets so that the water overflows the top of the skittle

Observe the color rings that appear on the coffee filter when if dries

Color Mystery

-Using one of the three markers, create “evidence” from the robbery crime scene (“1 Chemistry Lane” written on a piece of chromatography paper or coffee filter paper)

-Present the mystery that a robbery was committed and only the above address was found at the crime scene. Three suspects were found, each with a different type of black marker. The only way to find out who is the criminal is to test each culprit’s marker with the chromatography or filter paper.

-Have each group (of 2-4 kids) mark each piece of chromatography paper with a different black marker

-Observe the results of dipping the bottom of the paper into water and allowing the water to creep up the paper (do not submerge the markings in the water, simply allow for one edge to touch the water)

-Identify the “criminal” by matching the marker used to create the evidence with the marker from one of the culprits by matching the colors shown on the chromatography paper after dipped in water

Coloring (optional if time allows)

-Give the children paper and markers and encourage the students to observe how the mixtures of the different colored markers relate to the colors on the color wheel.

Time requirements

The experiment will take about an hour depending on how long the kids are allowed to experiment with the coloring on the paper.

Clean up

All of the paper, skittles, and cups can be thrown away. The water can be poured down the drain.

Reference

www.madsci.org/experiements/archive

Name__________________

Color Mystery

Drop water onto the skittle.

What colors appear? Can you identify them on the color wheel?

The Color Wheel

Yesterday, there was a robbery in a local bank. The police only recovered one piece of evidence. The evidence was a sheet of paper with an address written on it using a black marker. There were three suspects found near the crime scene with different black markers.

Ben was found with marker #1.

Sally was found with marker #2.

Carl was found with marker #3.

How will we figure out who is the real criminal?

First, place the paper with the evidence into one of the plastic cups. What colors appear on the paper?

Next, mark each sheet of paper with a different marker. Place these sheets of paper into the cups and watch what happens.

What colors appear using marker #1?

What colors appear using marker #2?

What colors appear using marker #3?

Who is the criminal?