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:
“Our institutions have a potent digestion, and may in time convert and assimilate to good all elements thrown in, however originally alien.”
—Herman Melville (1819–1891)
“Those who make a practice of comparing human actions are never so perplexed as when they try to see them as a whole and in the same light; for they commonly contradict each other so strangely that it seems impossible that they have come from the same shop.”
—Michel de Montaigne (1533–1592)
“The English were very backward to explore and settle the continent which they had stumbled upon. The French preceded them both in their attempts to colonize the continent of North America ... and in their first permanent settlement ... And the right of possession, naturally enough, was the one which England mainly respected and recognized in the case of Spain, of Portugal, and also of France, from the time of Henry VII.”
—Henry David Thoreau (1817–1862)