1Pour half a teaspoon of salt into a glass of water and mix it.
2Remove the eraser (including the metal part) from two pencils (use pliers to help).
3Sharpen both ends of each pencil to make double-ended pencils.
4Attach alligator clips to each terminal of the battery and then to each pencil tip (black part).
5Place the other ends of the pencils into the water (you should see gas bubbles start to be made).
How It Works
The gas bubbles forming around the pencils in the water are caused by electricity being used to split water molecules into the elements, hydrogen and oxygen. Hydrogen gas forms on one of the pencils, and oxygen gas forms on the other. The pencil that is making a lot more bubbles than the other is the hydrogen gas. This is because water has 2 hydrogen atoms for every 1 oxygen atom (H2O).
Check out the Full Lesson on Properties of Elements!
In this lesson, we learn that:
Elements are pure substance made of only 1 type of atom.
Each element has properties that can be used to identify it.
All elements are arranged in rows and columns on the periodic table.