Snakeater
If you have Potassium in a bottle it will be under a layer of mineral oil. The potassium reacts with Water/even to humid air to rapidly form hydrogen gas, which typically ignites from the heat of reaction. So if a person dumps a chunk of potassium into the 85% water
Lugols solution the resulting bang and flame could cause quite a spectacle. Of course after all the water reacted out you may have some
Iodine to react with the potassium, but the that pesky water vapor in the air will want to keep reacting and producing hydrogen. Here end-th the Chemistry lesson.