Question

Which solids do not have definite melting point ? And why ?

a) crystals
b) poly crystals
c) amphorous solids
d) quartz

Answer 1

a) crystalline solids are generally incompressible, meaning they cannot be compressed into smaller shapes. Because of the repeating geometric structure of the crystal, all the bonds between the particles have equal strength. This means that a crystalline solid will have a distinct melting point, because applying heat will break all the bonds at the same time.

b)poly crystals are semicristalline polymers. These have melting ranges but the range is different with different compounds

c)amorphous solids have large melting range. eg:glass. These are psedo solids and are called superfluids. Thus they soften as temperature increases and finally melt to a fluid.

d)quartz is a crystal thus it shows meting properties of crystaline solid.