If you leave a cup of water at room temperature it will turn into a gas spontaneously. But why don't oxygen and hydrogen gases found in the air, combine spontaneously and immediately, to form water when they are mixed at room temperature?

Can someone explain the compression of sound to me? Pretend I'm an 8th grader. Analogies please! I already get the particles vibrating thing😁 Thank you beautiful internet people! ❤️

So a friend of mine and I had the geekest argument in a bar. I said that any 2 objects (that don't produce heat themselves) become the same temperature given enough time. The example was a glass of water in a freezer @ -5 vs a glass of sand in the same freezer. I exclaimed that they will be the same temperature given time...he called me retarded. Please help. (I told him he was thinking heat latency...was then called retarded again)

Edit: We searched the internet for about 30 min for an answer, to no avail. I will surely need a theory/concept I can reference to throw in my buddies face. Its a bet.

It was formally run as a sub that had nothing to do with ferns. The only mod has a suspended account so I picked it up. If you like ferns head on over! I'll be building it up as I did /r/CrowBro when that sub became available.