Chromatography

Chromatography is the separation of liquids based on particle or molecule size. Chromatography is used to separate inks into the colors that make them up. Most inks are mixtures of colors and the ink will separate into bands of colors based on the size of the differnt ink molecules.The small particles move faster and will move further up the paper strip. Some black inks are actually made up of blue red, pink, and yellow.

Pairs or groups of students received a strip of filter paper and made a pencil line about 3 cm from the end. They then traced over the pencil line with a marker, dipped the paper into water and waited.

Chromatography can be used to separate any mixtures with different size particles and actually  gel  electrophoresis used for DNA analysis works on a similar principle.