Boron, arsenic, and antimony, among other substances, are used as dopants when added to a pure semiconductor material to alter its electrical characteristics.
Artificially produced gemstones[?] (such as Ruby (gemstone)) usually contain a dopant to identify them as such.
... it, but many of the provincial leaders did not. Trudeau thus was forced to include the notwithstanding clause to allow provinces to opt out of certain areas of the charter. ...