Foil is a metal "paper" made of aluminum, steel, tin, silver or gold with a thickness of 0.001 to 0.2 mm. The word "foil" comes from the Latin Fulgur - lightning, which means brilliant.
Earlier in the word "foil" the stress was on the first syllable, but now such stress is recognized as obsolete and the stress on the second syllable is generally accepted.
The gold leaf is called gold leaf. Gold foil is considered to be the thinnest foil. Its thickness is 0, 00001 mm.
The first sheet mirror was invented by the Venetians, putting tin foil on paper and pouring it with mercury. From above it was all covered with glass and the paper was taken out.
For the idea of wrapping foil chocolates, I should say thanks to the son of Frank Mars, the owner of the "Mars" factory, who wished chocolate one sunny day and it dripped into his hands, splattering his suit. The foil wrapper has become the main innovation of the successful entrepreneur.
In the United States, the first use of aluminum foil was in 1913, as a Life Savers candy wrapper. Fun fact: Tin foil was used to fill cavities in teeth until the 20th century. Now tin foil is not produced; it has been replaced with aluminum.
In the nuclear fusion of Mendelevium, the target was gold foil, onto which an insignificant amount (only about a billion atoms) of Einsteinium was electrochemically applied. Gold substrates for nuclear targets have also been used in the synthesis of other transuranic elements.
Some strange individuals wear foil hats, supposedly protecting from the zombie signals of the special services. But testing of such caps showed that they do not screen the signal at all, but can even amplify it.