Hey Ray: Invisible Messages
PITTSBURGH (KDKA) - I don't understand Snapchat.
The kids love it, but I don't get it, so today we are going to try a reverse "snap chat."
Let me explain.
Snapchat's messages disappear after someone reads them, so we are going to do the opposite. An experiment that has the message appear before you read it.
That might sound like a text message, but this will be a little more "old school". Especially since we are going to use paper to make an invisible message.
To do this we will use that paper and some lemon juice. We will then brush our message on the paper with a cotton swab.
It doesn't look like much because we are writing an invisible message.
To get the message to appear, we will need some heat. For that, are going to use a candle.
Since a flame will be present, and you are going to put paper near it, you should only perform this experiment outside and away from flammable objects. You should also have a fire extinguisher nearby and only perform this experiment with a responsible adult.
Now, we will hold our papers with the message above the flame. You should sort of "toast" the paper like a marshmallow. You will notice that your message begins to appear.
So, how does that work?
The lemon juice is absorbed into the paper's fibers. When we added heat, it broke down the chemical bonds of the juice, releasing carbon. That carbon, when exposed to the air is oxidized, making it darker.
Different substances will char at different temperatures. Lemon juice chars, or discolors, at a much lower temperature than the paper, revealing the message.
You can also try this with lime juice or milk.
Now, you can write an invisible message on a piece of paper, and it won't appear until you heat it up.
Just like a reverse Snapchat!
