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:
“The three great elements of modern civilization, gunpowder, printing, and the Protestant religion.”
—Thomas Carlyle (17951881)
“The opening of large tracts by the ice-cutters commonly causes a pond to break up earlier; for the water, agitated by the wind, even in cold weather, wears away the surrounding ice.”
—Henry David Thoreau (18171862)
“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 mans parents; Boston wants to know about his grandparents.”
—Cleveland Amory (b. 1917)