Chemistry
The compound is radioactive due to the radioactivity of thorium. Thorium dioxide can be used as a nuclear fuel. (Refer to the article of thorium for more information on this application.) The high thermal stability of thorium dioxide allows applications in flame spraying and high temperature ceramics. Thorium dioxide was the primary ingredient in the X-ray contrast medium Thorotrast. Use of Thorotrast was abandoned when it was found to be a carcinogen, sometimes causing cholangiocarcinoma. Today, barium sulfate is the standard X-ray contrast agent. Thoria has the fluorite crystal structure. This is uncommon among binary dioxides (other examples include cerium dioxide, hafnium dioxide, uranium dioxide and plutonium dioxide). The band gap of thoria is about 6 eV.
Read more about this topic: Thorium Dioxide
Famous quotes containing the word chemistry:
“If thought makes free, so does the moral sentiment. The mixtures of spiritual chemistry refuse to be analyzed.”
—Ralph Waldo Emerson (1803–1882)
“...some sort of false logic has crept into our schools, for the people whom I have seen doing housework or cooking know nothing of botany or chemistry, and the people who know botany and chemistry do not cook or sweep. The conclusion seems to be, if one knows chemistry she must not cook or do housework.”
—Ellen Henrietta Swallow Richards (1842–1911)
“For me chemistry represented an indefinite cloud of future potentialities which enveloped my life to come in black volutes torn by fiery flashes, like those which had hidden Mount Sinai. Like Moses, from that cloud I expected my law, the principle of order in me, around me, and in the world.... I would watch the buds swell in spring, the mica glint in the granite, my own hands, and I would say to myself: “I will understand this, too, I will understand everything.””
—Primo Levi (1919–1987)