Hot foil trick Hot foil trick The hot foil trick is a magic trick in which the magician places a small piece of tin or aluminium foil in a volunteer's hand, and the foil begins to rapidly increase in temperature until the volunteer has to drop it to avoid scalding their hand, and the foil is reduced to ashes on the ground. This effect is achieved by, shortly before performing the trick, surreptitiously exposing the foil to a chemical (such as mercury(II) chloride ) which will cause it to rapidly oxidise. This trick can be very dangerous, since many of the chemicals used
FOIL method FOIL method In elementary algebra, FOIL is a mnemonic for the standard method of multiplying two binomials—hence the method may be referred to as the FOIL method. The word "FOIL" is an acronym for the four terms of the product: The general form is: Note that is both a "first" term and an "outer" term; is both a "last" and "inner" term, and so forth. The order of the four terms in the sum is not important, and need not match the order of the letters in the word FOIL. The FOIL method is a special case of a more