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.
Read more about this topic: Metalloid
Famous quotes containing the words elements, commonly and/or recognized:
“The elements of success in this business do not differ from the elements of success in any other. Competition is keen and bitter. Advertising is as large an element as in any other business, and since the usual avenues of successful exploitation are closed to the profession, the adage that the best advertisement is a pleased customer is doubly true for this business.”
—Madeleine [Blair], U.S. prostitute and “madam.” Madeleine, ch. 5 (1919)
“The slight reproach to which the virtue of patriotism is commonly liable, the noble are most likely to incur.”
—Henry David Thoreau (1817–1862)
“The common goal of 22 million Afro-Americans is respect as human beings, the God-given right to be a human being. Our common goal is to obtain the human rights that America has been denying us. We can never get civil rights in America until our human rights are first restored. We will never be recognized as citizens there until we are first recognized as humans.”
—Malcolm X (1925–1965)