and, in light of their malleability, led to the first attempts to craft metal ornaments, tools, and weapons.

In 1817, German chemist Leopold Gmelin divided the elements into nonmetals, light metals, and heavy metals. Light metals had densities of 0.860-5.0 g/cm³; heavy metals 5.308-22.000. The term heavy metal is sometimes used interchangeably with the term "heavy element". For example, in discussing the history of nuclear chemistry,