On Friday, whilst discussing Autumn and the leaves changing colour, Mrs Parry demonstrated how to perform chromatography to separate the colours found in leaves. Afterwards, she asked Bluebirds to be both detectives and scientists to help establish which staff member’s pen had written a note left in the staffroom, admitting they had taken the last doughnut! There were three possible suspects! The children conducted the experiment below:
The children had pens belonging to Mrs Butterworth, Miss McClelland and Mr Johnston. They had to match their ink to the one that had written the apology note to identify who had taken the cake.
Mr Johnston was found to be guilty…..the mystery was solved! Well done Bluebirds!
The children found out that Ink is not made of just one pigment (colouring stuff). To make one colour, you need several pigments and different pen brands use different mixtures of pigments. Some pigments are better at dissolving in the solvent than others. This means that when the solvent travels up the paper strip, some pigments will “follow” it to the top while others will lag behind. This way you can separate the different pigments (solutes) inside the ink.