Questions

An amorphous or non-crystalline solid is a solid that lacks the long-range order that is characteristic of a crystal. In Brief, An amorphous solid is any noncrystalline solid in which the atoms and molecules are not organized in a definite lattice pattern. Such solids include glass, plastic, and gel.

Quartz glass (SiO2) is an amorphous solid due to its short range order of constituent particles. Note Quartz is a crystalline solid while quartz glass is an amorphous solid.

The given number puzzle can be soved in two ways.

Logic 1 ::

Row 1  - 2 x 3 = 6 , 6 x 3 = 18

Row 2  - 4 x 5 = 20 , 20 x 5 = 100

Row 3  - 3 x 7 = 21 , 21 x 7 = 147

Hence, the missing number could be 3.

Logic 2 ::

Row 1 - 6 x (2+1) = 18

Row 2 - 20 x (4+1) = 100

Row 3 - 21 x (6+1) = 147

Hence, the missing number could be 6.

Therefore, 3 or 6 is the right answer.