What would happen to a bowl of jello sitting in a fridge uncovered?

Two things happen: # The water in the jello evaporates. This is a slow process, but it leaves a thicker 'skin' on the exposed surfaces. Eventually you will end up with a hard slightly translucent mass that is much smaller. # The Gelatin absorbs the flavors and smells in the refrigerator. You can end up with onion or fish flavored jello!