How bout a gas that has the explosive power of C4

it defuses VERY slow and doesn't repel itself very well, its also very heavy and doesn't move quick to pressure like other gases, if you drop the temperature down low or increase pressure it liquifies into what would be good as C4, under a different element name

this would make for good explosive clouds that would set off all the gas

say you open the top to a can of this gas, the gas rushes out because its under IMMENSE pressure but it tends to stay in one area under normal or higher pressure between particles, the gas would cloud up and then you light one spark of fire, and it sets this whole cloud off.

this isn't like GAS, GAS is very flammable but not very explosive and it expands and moves very quickly because of pressure.

Another suggestion is a Wall that blocks gas but allows everything else.

Also, a temporary CLNE, emits a certain amount of stuff or emits for a timed amount.

an explosive that emits little fire but LOTS of pressure. but doesn't explode under pressure, this could be the solid form of the gas mentioned above

and I want to suggest one more thing but it escapes me.

singularity
but its not very thick and it acts like regular Gas

I really want a thick explosive gas, so that I can make what is known as a Gas Cloud Bomb, an bomber drops this bomb and it explodes a gas, and then it ignites.

Sort of like a Daisy Cutter