Japanese 10-yen makes of copper.
Old 10-yen coins are often oxidized, and the color is dark blown. In this photo, left is new coin in 2012, middle one is in 1974, and right one is in 1966.
Let’s make these coins shine.
We prepared two liquids.
One is squeezed juice of a lemon.
After these coins are sunk in two liquids, wait 3 minutes.
You can observe the clean coin which was sunk in the lemon juice. However, the coin in vinegar is unchanged.
8 hours later
24 hours later
Right black blown is a non-sunk coin.
Other one is vinegar.
After these coins are sunk in two liquids, wait 3 minutes.
You can observe the clean coin which was sunk in the lemon juice. However, the coin in vinegar is unchanged.
8 hours later
You can observe the efficacy of vinegar.
24 hours later
The effect of deoxidization is fantastic.
Hope you and your kids enjoy the exam.
