Which of the following features are not shown by quartz glass?
(i) This is a crystalline solid.
(ii) Refractive index is the same in all the directions.
(iii) This has a definite heat of fusion.
(iv) This is also called supercooled liquid
The answer is the option (i, iii) Since quartz glass is an amorphous solid, it has no definite heat of fusion. This is due to short-range order of molecule. Also known as super cooled liquid, quartz glass is isotropic in nature.