Both quartz and glass are made up of silica `(SiO_(2))`. However, quartz exists in crystalline form, whereas glass in amorphous form. Why is this difference?

Crystalline quartz (SiO_(2)) is-

Borax when heated on platinum wire forms a glass like bead which is made up of :

What makes a glass different from a solid such as quartz? Under what conditions could quartz be converted into glass?

What makes a glass different from a solid such as quartz? Under what conditions could quartz be converted into glass?

An element occupies group No.14 and period number 2 exists in different allotropic forms. One form of this element has lubricating property (A). Another form is the hardest substance (B). New allotrope of this element is named as Buckyball' (C) and it is superconducting. Identify the element, (A) (B) and (C).

Silicon is second most abundant element occurring in earth crust. It is always found in combined state. Silicon exists in two allotropic forms,amorphous & crystalline. The compounds of silicon are carborundum, silicon, silicate,glass etc. Silicones are organosilicon polymer & silicates are metal derivatives of silicic acid. While carborundum are obtained by heating mixture of sand, carbon & common salt. The structural unit of silicates is

Silicon is second most abundant element occurring in earth crust. It is always found in combined state. Silicon exists in two allotropic forms,amorphous & crystalline. The compounds of silicon are carborundum, silicon, silicate,glass etc. Silicones are organosilicon polymer & silicates are metal derivatives of silicic acid. While carborundum are obtained by heating mixture of sand, carbon & common salt. Which type of linkage is present in silicones ?

A drop of some liquid of volume 0.04 cm^3 is placed on the surface of a glass slide. Then another glass slide is placed on it in such a way that the liquid forms a thin layer of area 20 cm^2 between the surfaces of the two slides. To separate the slides a force of 16 xx 10^5 dyne has to be applied normal to the surfaces. The surface tension of the liquid is (in dyne- cm^(-1) )