[The Great RJ]

In one of my college chemistry classes our instructor did a demonstration with a single small hydrogen filled balloon. The explosion sure got our attention.

[Bikkuri]

I remember shop/welding class.
The instructor filled a balloon with oxygen.. poof.
Then acetylene... poof.

Then, he took us all outside, after he filled with oxy/acetylene... He said RUN.. (we ran), then BOOOOOOOOM ✴️‼️