1. Metalloids
2. Semimetallicity?
3. Polonium and Astatine Are Not Semimetals
4. Although Holt, Rinehart, and Wilson reached the same conclusion as Hawkes on the classification of polonium and astatine, their analysis is less thorough, in terms of breadth and depth, than that of the latter author. Accordingly, their work is not further considered here. Holt A.; Rinehart B.; Wilson C. Why polonium and astatine are not metalloids in HRW texts. c. 2007.http://go.hrw.com/resources/go_sc/periodic/Po_At_Metalloids.pdf(accessed Oct 2013) .
5. For example, Brande and Cauvin (1845) classified the elements as gases (O, H, and N); halogens; metalloids (S, P, C, B, and Si?)—“resemble the metals in certain respects, but are in others wildly different”; and metals, predating Mendeléeff’s announcement of the discovery of periodic law in 1869. As another example, Tilden (1876) subsequently divided the elements into (“basigenic”) true metals, metalloids (“imperfect metals”), and (“oxigenic”) nonmetals. He counted H, As, Sb, Bi, and Te as metalloids, along with Ti(?), Zr, V, Nb(?), Ta(?), Mo, W, and U. Mendeléeff (1891) similarly regarded tellurium as forming “a transition from the metals to the non-metals”.Brande, W. T.; Cauvin, J.A Dictionary of Science, Literature and Art;Harper & Brothers:New York, 1845; p223;