Mark (unit) Mark (unit) The Mark (from Middle High German: Marc, march, brand) is originally a medieval weight or mass unit, which supplanted the pound weight as a precious metals and coinage weight from the 11th century. The Mark is traditionally a half pound weight and was usually divided into 8 ounces or 16 Lot. The significance of the "Cologne Mark" (Kölner Mark) in the German-speaking areas corresponded to about 234 gram. Like the German systems, the French poids de marc weight system considered one "Marc" equal to half-a-pound (8 ounces). Like the pound of 12 troy ounces (373 g), the mark
Heavy metals metals in form or appearance"). This suggestion was ignored; the new elements came to be recognised as metals, and the term metalloid was then used to refer to nonmetallic elements and, later, elements that were hard to describe as either metals or nonmetals. An early use of the term "heavy metal" dates from 1817, when the German chemist Leopold Gmelin divided the elements into nonmetals, light metals, and heavy metals. Light metals had densities of 0.860–5.0 g/cm; heavy metals 5.308–22.000. The term later became associated with elements of high atomic weight or high atomic number. It is sometimes used interchangeably