First thing first, if its outside, animals can get to it.
It can start to smell and get gross
It will dry out over time as long as it is uncovered, if it is covered it will get moldy
It rots.
ikirr
Nothing will happen unless it evaporates. If left uncovered at 100C Sulfuric acid will dehydrate to form Sulfur trioxide and water.
it will burn
no
If you clean out the recyle bin, then whetever was in it is gone for good.
it would dry out
nothin happens
it will get unhappy
recycle bin
Organic matter in a compost bin decomposes as a result of bacteria action.