Lemon juice is a kind of fruit juice, which is mainly used for drinking and flavoring. In addition to the above two functions, lemon juice has a special function, that is, writing on paper with lemon juice can make the words "invisible" after drying. Lemon juice contains vitamin B 1, vitamin B2, vitamin C and other nutrients, which can't be seen when written down.
Lemonade contains an ingredient called cellophane, which can reduce the ignition point of paper. As long as the paper is baked with fire or heated with iron, ironing board and hair dryer, the writing part of lemon juice will be burnt first and yellow words will appear. White vinegar, strong brine, milk and water can also be used to write secret letters.
Write a secret letter with strong salt water: dip a pen in some strong salt water and write down the words. When the concentrated brine dries, the water evaporates, leaving dry salt on it, forming a rough layer. At this time, using a pencil to understate, the pencil will leave traces on the rough salt surface, and the words will appear.
Method of writing invisible characters with lemon juice
1. Pour a tablespoon of lemon juice into a cup, preferably freshly squeezed lemon juice.
2. Soak the bottom of a cotton swab or small brush in lemon juice.
3. Write on plain paper with a cotton swab or brush dipped in lemon juice. When the paper is dry, you can see that the handwriting is invisible.
4, heating can make the text appear, there are three main methods of heating:
(1) Put the paper next to the light bulb and heat it.
(2) Ironing with an iron is effective. You can put a cloth between the iron and the paper to keep the surface of the iron clean.
(3) Put the paper beside the stove, and be careful not to burn it. If the child does this experiment, parents should be present.