1) Bubbled a bit and the part that went into liquid got lighter in color!
2) The vinegar ones turned greenish and didn't 'dry', when rinsed with water they turned darker but NOT green and dried, the paper towel holding vinegar pennies turned green but the paper towel holding water ones didn't change a bit.
3) A few bubbles and the part touching liquid turned darker
-at 2 minutes there were few bubbles
-at 4 minutes there were still bubbles and it turned darker
-at 8 minutes there were still bubbles, but now it was very dark
-at 10 minutes it was totally black!
