Magic Dye
This activity, produced by Solar Spark, uses "magic dye", a mixture of three different dye molecules. The mixture contains a yellow disperse dye, a direct blue dye and an acid red dye. When a fabric is put into the mixture, the dyes only attach to the types of fabrics they can bond well with. For example, the blue and yellow…
Newton Wheel
This activity, from Solar Spark, allows students to investigate light and the eye. A template is provided that students can colour to produce a Newton Wheel. White light is made up of lots of different colours and by spinning the colours on the disc, the eye combines the spinning colours and sees the disc as if it were white. The…
Make Your Own Spectrometer
From Solar Spark, this simple activity allows students to make a spectrometer using a card box and a compact disc. The compact disc acts as a diffraction grating and splits the light being observed into its constituent wavelengths. This gives the colours of the rainbow when viewing white light. This type of analysis is applied in…
Chlorophyll Fluorescence
From Solar Spark, this activity allows students to see how chlorophyll can be energised and how this causes it to fluoresce. Chlorophyll in plant leaves absorb red light and pass the energy on to other parts of the plant, hence leaves look green. But if there is nowhere for the energy to go, it gets released as light again. This…
Tyndall Effect: Red Sky at Night
Produced by Solar Spark, this simple activity helps to answer the simple, yet complex question: Why is the sky blue and the sunset red? It's all to do with light scattering and the Tyndall Effect and can be easily demonstrated using a suspension of milk in water. Milk particles suspended in the water cause any light going…
Plastic from Milk
Produced by Solar Spark, this activity allows students to make their own plastic from vinegar and milk. Milk contains casein in a form that is soluble in water. Making the milk acidic by adding vinegar makes the casein insoluble so the milk separates into a solid and a liquid known as curds and whey. Removing the water by filtering…
Solar Cells and Light Absorption
Produced by Solar Spark, this activity looks at the relationship between light and absorption in solar cells. Using a photovoltaic cell and different colour acetate sheets, it demonstrates the ability of solar cells to absorb at different wavelengths of the electromagnetic spectrum and shows how the more it can absorb, the more power…
Solar Cell Straws
Produced by Solar Spark, this is a simple practical activity that can be used to show how a solar photovoltaic cell works. During a 45-60 minute session, students make solar cells out of cheap and readily accessible materials. The mechanism behind the solar cell is similar to that used in a dye-sensitised solar cell (DSSC) but uses…
Anodising Titanium
By Solar Spark, this activity explores the relationship between light scattering and colour through anodising. This is the electrochemical process used to thicken the protective oxide layer found on several metals. Aluminium is the most common metal treated in this way, but others, including titanium can also be anodised. Thick…
Electrochemical Writing
From Solar Spark, this practical activity explores the reactions at electrodes in an electrical circuit. A solar cell contains two electrodes. Different reactions happen at each electrode so that electrons can move around the circuit to give an electric current. In this experiment students use filter paper soaked in sodium chloride…
Make a Graetzel Solar Cell
Produced by Solar Spark, this activity allows students to make a photovoltaic cell in the school laboratory. A solar cell uses light from the sun to produce electricity. A type of solar cell, called a dye-sensitised solar cell (DSSC), can be made. This type of cell is cheaper than other solar cells, and is now produced commercially.…