As a young Boy Scout (apparently in the very BAD Boy Scout Troop) we used to make Alka-Seltzer bombs by putting Alka-Seltzer and water into a jar, screwing the lid on tightly, waiting a bit and they throwing it against something hard. But then I was about 12 years old.
This was also the Boy Scout troop where before meetings we would lie in the bushes in front of the church where we met and with our BB guns try to shoot the give away dishes on display outside the gas station across the street from the church. Not exactly good Boy Scout behavior.
I was also part of a delinquent Boy Scout troop. We were kicked out of a jamboree for throwing our breakfast eggs...