Why DIY Electro Dough Conducts Electricity.
by techwillsaveus in Circuits > Electronics
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Why DIY Electro Dough Conducts Electricity.
This is an experiment to show why it is the salt in DIY Electro Dough that conducts the electricity. The common misconception is that it is the water that conducts electricity, but it is actually the salts and minerals contained within it.
You will need:
- 1 glass
- De-ionised / Distilled Water (used for car batteries so buy from garage or defrost freezer ice)
- Salt
- 4 AA batteries
- Electro Dough made to our recipe (bought play dough works but has higher resistance)
From the DIY Electro Dough Kit:
- 1 LED
- 3 Crocodile clips
- 1 Battery Pack
Put the batteries in the battery pack and check it is turned on.
Take the 1st crocodile clip. Push 1 end into the first model.
Take the 2nd crocodile clip. Push 1 end into the second model and clip the other end onto the positive red wire of battery pack.
Take the 3rd crocodile clip. Clip one end onto the negative black wire of the battery pack.
Link the two dough models with an LED (and buzzer), making sure the long leg (or red buzzer wire) is in the model connected directly to the battery pack.
Test the circuit by touching the two loose crocodile clips together. The LED should light.
If it does not light, check: The LED is the right way round (polarity) The dough models are not touching (short circuit) The battery pack is turned on.
Put both crocodile heads into the glass of distilled water. The LED should now NOT LIGHT (and the buzzer should not buzz). There may be a faint squeal if using a buzzer, but this will just be tiny impurities in the water.
Why?:
This is because pure water has no free electrons to pass on and make the electrical current. Pure water (H2O) does not conduct electricity.
Take a teaspoon of table salt and pour into glass of distilled water.
The light should now TURN ON.
Why? :
Now there is table salt or sodium chloride (NaCl) in the water, this DOES have free electrons to pass on, and make the electrical current flow. It is the impurities in water that conducts electricity not the water itself.
This ability to conduct electricity is why we put SALT in DIY Electro Dough