Does tin foil decompose?
Tin foil over time will decompose. However it will not turn to its original state. It will break into pieces and mix with soil.
It depends on the status of the can.Tin cans (tin coated steel cans) will rust away within a few years if exposed to moisture, On camping trips it is common to toss empty cans in the fire to remove protective paint or plastic which protects the metal from oxidation to hasten the process. In dry conditions they can last for many decades.
Actual tin foil was superseded by cheaper and more durable aluminum foil after World War II, and aluminum foil is sometimes confused as "tin foil" because of its similarity to the former material. Tin was first replaced by aluminum starting in 1910, when the first aluminum foil rolling plant, Dr. Lauber, Neher & Cie., Emmishofen was opened in Kreuzlingen, Switzerland. The first use of foil in the United States was in 1913 for wrapping Life…
Tin itself is a chemical element with the symbol Sn (Latin: Stannum) and atomic number 50. Tin is obtained chiefly from the mineral cassiterite, where it occurs as tin dioxide, SnO2. Actual tin foil was superseded by cheaper and more durable aluminum foil, which is sometimes called "tin foil" because of its similarity to the former material.