If I recall correctly SF6 is even better for that, but heavy gases have tenedency to settle down in such circumstances. Putting volounteer on the head was the right thing to do.A chemist friend claims that Argon would mix so well with air that it shouldn't really have been a problem, so maybe the volunteer/idiot just panicked.
My first biology experiment was with the girl next door, who was about a year older than me and was usually the instigator of any trouble I ever got into.My first biology experiment:
When I was a kid, my neighbor and I dumped everything we could find and fit into the "trunk" of her Big Wheels (the little plastic box on the back). That included stuff like sand, weeds, bugs, we gave it a good stir, then let it sit for a few days until her mom discovered it. :yuck: Her mom made us clean it, and we had to draw straws to decide who would open the lid to dump it out. Had to hold our noses to even get close to it.