Question

which crystalline solid has least melting point​

Answer 1

Classes of Crystalline Solids

Type of Crystalline Solid Examples (formulas) Melting Point (°C)

Ionic NaCl CaF2 801 1418

Metallic Hg Na Au W -39 371 1064 3410

Covalent network B C (diamond) SiO2 2076 3500 1600

Molecular H2 I2 NH3 H2O -259 114 -78 0

Answer 2

There are four types of crystalline solids: Ionic solids—Made up of positive and negative ions and held together by electrostatic attractions. They're characterized by very high melting points and brittleness and are poor conductors in the solid state. An example of an ionic solid is table salt, NaCl.