Scientific winter decorations
Can drawings also conduct electric current?
Warning: only under adult supervision.
- calcium nitrate;
- graphite dust;
- beaker with water;
- wooden stick;
- 9 V battery;
- crocodile clips.
Prepare an aqueous solution of calcium nitrate in a beaker and add some graphite dust to create electrically conductive ink. Use this ink to draw a snowflake. Connect a 9 V battery to the snowflake with crocodile clips and put LEDs on the graphite lines to create a complete circuit – the LEDs light up!
Graphite has a special structure consisting of flat layers of carbon. Electric current can flow along these layers. Adding an electrolyte solution to its powder makes electrically conductive ink. An electrolyte is a substance that dissociates into charged particles (ions) in an aqueous solution, and therefore can also conduct electric current. Calcium nitrate is a perfect example. The electrolyte solution helps electrons move from one particle of graphite to the next. Thus, a thick mass is obtained, which you can use to make real liquid "wires" in an electrically conductive pattern!
A similar experiment is included in the “Zinc-carbon battery” set from the MEL Chemistry subscription!