Lists of metalloids cluster. Cluster 1 (93%) = B, Si, Ge, As, Sb, Te; cluster 2 (44%) = Po, At; cluster 3 (24%) = Se; cluster 4 (9%) = C, Al; cluster 5 (5%) = Be, P, Bi; cluster 6 (3%) = Sn; and cluster 7 (1%) = H, Ga, S, I, Pb, Fl, Mc, Lv, Ts. The resulting geometric trend line has the formula y = 199.47e and an R value of 0.9962. The elements commonly classified as metalloids are boron, silicon, germanium, arsenic, antimony and tellurium. The status of polonium and astatine is not settled. Most authors recognise one or the
Metalloid otherwise the crystalline form results. These compounds are used in chemical, domestic, and industrial glassware and optics. Boron trioxide is used as a glass fibre additive, and is also a component of borosilicate glass, widely used for laboratory glassware and domestic ovenware for its low thermal expansion. Most ordinary glassware is made from silicon dioxide. Germanium dioxide is used as a glass fibre additive, as well as in infrared optical systems. Arsenic trioxide is used in the glass industry as a decolourizing and fining agent (for the removal of bubbles), as is antimony trioxide. Tellurium dioxide finds application in laser