which metalloid is used in formation of glass?
Phosphorus, selenium, and lead.
Metalloid
Phosphorus, selenium, and lead, 
what is the basis of arranging the elements in the modern periodic table Atomic number, electron configuration, and recurring chemical properties. what is the purpose of the table? UNANSWERABLE why is called so? Because of the tabular display of the chemical elements. what sorts of elements can we see in it? Nonmetallic elements such as metalloids,  groups of families of elements and elements having metallic lustre. can you name a few of the first form? Boron, silicon, germanium, arsenic, antimony, and tellurium. where are they commonly applied? Alloying components, biological agents, catalysts and flame retardants. what do they do being the second type? They have medical applications, can be used in insecticides and herbicides, also they have antiseptic, antifungal, and antiviral properties. how are they used in making glass? As a glass fibre additive.
wiki:8264399
Metalloid [SEP] Glass formation
Tellurium dioxide finds application in laser and nonlinear optics. Amorphous metallic glasses are generally most easily prepared if one of the components is a metalloid or "near metalloid" such as boron, carbon, silicon, phosphorus or germanium. Aside from thin films deposited at very low temperatures, the first known metallic glass was an alloy of composition AuSi reported in 1960. A metallic glass having a strength and toughness not previously seen, of composition PdPSiGe, was reported in 2011. Phosphorus, selenium, and lead, which are less often recognised as metalloids, are also used in glasses. Phosphate glass has a substrate of phosphorus pentoxide (PO), rather than the silica (SiO) of conventional silicate glasses.