Elements Less Commonly Recognized As Metalloids
There is no universally agreed or rigorous definition of the term metalloid. So the answer to the question "Which elements are metalloids?" can vary, depending on the author and their inclusion criteria. Emsley, for example, recognized only four: germanium, arsenic, antimony and tellurium. James et al., on the other hand, listed twelve: boron, carbon, silicon, germanium, arsenic, selenium, antimony, tellurium, bismuth, polonium, ununpentium and livermorium. As of 2011 the list of metalloid lists recorded an average of just over seven elements classified as metalloids, per list of metalloids, based on a sample size of 194 lists.
The absence of a standardized division of the elements into metals, metalloids and nonmetals is not necessarily an issue. There is a more or less continuous progression from the metallic to the nonmetallic. A specified subset of this continuum can potentially serve its particular purpose as well as any other. In any event, individual metalloid classification arrangements tend to share common ground (as described above) with most variations occurring around the indistinct margins, as surveyed below.
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Famous quotes containing the words elements, commonly and/or recognized:
“Let us have a fair field! This is all we ask, and we will be content with nothing less. The finger of evolution, which touches everything, is laid tenderly upon women. They have on their side all the elements of progress, and its spirit stirs within them. They are fighting, not for themselves alone, but for the future of humanity. Let them have a fair field!”
—Tennessee Claflin (1846–1923)
“Most commonly revolt is born of material circumstances; but insurrection is always a moral phenomenon. Revolt is Masaniello, who led the Neapolitan insurgents in 1647; but insurrection is Spartacus. Insurrection is a thing of the spirit, revolt is a thing of the stomach.”
—Victor Hugo (1802–1885)
“It used to be said that, socially speaking, Philadelphia asked who a person is, New York how much is he worth, and Boston what does he know. Nationally it has now become generally recognized that Boston Society has long cared even more than Philadelphia about the first point and has refined the asking of who a person is to the point of demanding to know who he was. Philadelphia asks about a man’s parents; Boston wants to know about his grandparents.”
—Cleveland Amory (b. 1917)