[5Madman2]

We made it in Chemistry class when I was in High School

Nitrogen Triiodide

Iodine and concentrated ammonia

Filter out the residue

When dry-very sensitive-air currents set it off

Had a tray of it go off in my face when I picked it up when I was in HS. Made a bang and scared the crap out of folks (Including me) but no damage done

[Noamie]

That’s fascinating.

Did it have a color or do you think it would “dye” clothing?

(Sounds maybe too sensitive to actually use like Al Qaeda claims?)

[BillM]

You didn’t mention that it turns you purple!

It is actually really dangerous if you get enough of it in one place!

[Cyber Liberty]

Nitrogen Triiodide

I made my share of that stuff. The ammonia would be a tip-off though....

[Abathar]

Sodium chlorate in hydrated solution, let it dry.

Do it with paper towel, goes BANG real well...

[OregonRancher]

We painted it on the floor of a busy aisle before work began.
Secretaries with their high heels set it off..hilarious

[NonValueAdded]

We’d coat the chalkboard (remember chalk?) erasers with it and wait for the purple smoke.

[Sola Veritas]

“Nitrogen Triiodide”

Nope, that cannot be it. More likely to be Triacetone triperoxide TATP.

[Blueflag]

Yep. That and tetra ammonium chloride IIRC. Fun stuff ...

[editor-surveyor]

That was the first thing I thought of when I read the thread title.