We got the copper coin (of the game center), which was almost black, but after we put it into the vinegar, it turned brown! And the vinegar turned blue. This is due to the redox reaction of copper, but my 5yo daughter who loves Elsa said "Wow, that's THE MAGIC...!"🪄 https://t.co/8M8dyJnvX6
16 September 2022 06:16