I don't know which pin I actually looked at.
For our project I considered using a turkey baster, an eye dropper or an empty syringe. I decided to use straws.
You know how liquid stays in the straw when you put your finger on the top? We used that method to transfer the vinegar to the baking soda.
It was fun! I figured there was science behind the method and reaction, but neglected to find out and explain it!
Maybe someday he'll take a Physics class and explain it to me, ha ha!