Possibly. Elephants, no. Rabbits and squirrels- yes, with a head shot. A person? Depends on energy of bullet, and location of wound.
None
You use a 22. rifle
Definitely Yes.
A 275-lb man. If you place the shot just right, a .22 could kill anything.
Yes. But I suggest using hunting pellets.
Definitely Yes it can.
Rodents and small game.
Raccoons and large possums are the largest things.
Yes, a shotgun blast to the heart would kill instantly.
That's a very vague question. If you mean a .22 caliber rifle, the techincal answer is, almost anything. It's possible for a .22 to kill almost any animal, it just isn't extremely likely in some cases.
With a properly placed shot, anything from a .22 long rifle on up.
Normally a 600-700 fps air rifle will kill a rabbit at around 30-40 yards away. So this will include a .22 caliber air rifle or if your looking for something with less power that will just kill birds, try looking for a .177 or .20 caliber air rifle but if you are looking to hunt game like rabbits go for .22