1. A lemon or lemon juice
2. A cup or a bowl or a container
3. A piece of paper
4. A paint brush or a piece of cotton
5. A lighter or a burner
1. At first slice the lemon and squash it to get lemon juice from it. Contain the lemon juice in a cup or a bowl or a container.
2. Then dip the paintbrush into the cup/bowl where you have put the lemon juice.
3. Now use the paint brush to write anything on the paper. (Usually it’s a secret message because the writing is invisible! :p)
4. Let the writings dry on the paper.
5. Now light the lighter or the burner and place the paper containing invisible secret message near the fire. Be very careful not to let the paper on fire. Just make sure that the paper will get quite a bit of heat from the lighter or the burner.
6. Now observe what happens.
The more heat you give the paper the more your writings become visible again. Eventually your invisible or secret message will not be an invisible or secret message anymore. It will be completely visible.
When we write use lemon juice on the paper and let it dry the areas of the paper which contain lemon becomes more sensitive or vulnerable to heat. So the area of the paper containing lemon juice takes much less time to be heated. In simple words it takes much less time to burn the areas of the paper containing lemon juice. So when we place the paper close to a lighter or burner fire i.e. give it heat the areas containing lemon juice burns much more than the areas not containing lemon juice. Because the areas containing lemon juice burns more than other places of the paper or they become darker. That’s why the lemon juice writings become visible again. Sometimes only the areas containing lemon juice burns and the rest of the papers remain unaffected.
MORE EXPERIMENTS FOR YOU :
1. Try this experiment using vinegar to see what happens.
2. Try this experiment using Orange juice to see what happens.3. Try this experiment using Onion juice to see what happens.