Polonium were marketed by Firestone from 1940 to 1953. While the amount of radiation from the plugs was minuscule and not a threat to the consumer, the benefits of such plugs quickly diminished after approximately a month because of polonium's short half-life and because buildup on the conductors would block the radiation that improved engine performance. (The premise behind the polonium spark plug, as well as Alfred Matthew Hubbard's prototype radium plug that preceded it, was that the radiation would improve ionization of the fuel in the cylinder and thus allow the motor to fire more quickly and efficiently.) Polonium is
Polonium dichloride Polonium dichloride Polonium dichloride is a chemical compound of the radioactive metalloid polonium and chlorine. Its chemical formula is PoCl. Polonium dichloride appears to crystallise with an orthorhombic unit cell in either the "P"222, "P"mm2 or "Pmmm" space group, although this is likely a pseudo-cell. Alternatively, the true space group may be monoclinic or triclinic, with one or more cell angles close to 90°. Assuming the space group is "P"222, the structure exhibits distorted cubic coordination of Po as {PoCl} and distorted square planar coordination of Cl as {ClPo}. PoCl can be obtained either by halogenation of polonium metal or