It rots.
I have kept an open #10 can of Signature brand sausage gravy in the refrigerator, uncovered, for a week. I havent had any food poisoning.
no
Flies and bees will both sit on uncovered food. Food should always be covered especially when outside in the elements.
when food is uncovered for a long time micro organisms adapt the food which causes damage to our health. in covered food micro organisms cannot occupy it
it is not healthy
Assuming you mean "uncovered in the refrigerator, what happens is that they dry out - badly - and they also "pollute" each others flavors. The applesauce will taste like broccoli, etc.
Biological
Eating food that is left uncovered can expose it to contaminants such as dust, insects, and bacteria, increasing the risk of foodborne illnesses. Additionally, uncovered food can lose moisture and flavor, compromising its quality and taste. To ensure safety and maintain freshness, it's best to cover food or store it properly.
After Napoleon's men uncovered the Rosetta Stone, the Stone was shipped to Europe and (obviously) kept there.
Soup
To roast food (especially meat) is to bake it, uncovered in an oven or on a spit.
It is not good to eat uncovered food because many of the harmful microorganisms spoil the food making us fall ill