Classification of Crystalline Solids

Classification of crystalline solids

Table:  Some characteristics of different types of crystalline solids

 

 Types of Solid

Constituents

Bonding

Examples

Physical Nature

M.P.

B.P.

Electrical Conductivity

Ionic

Positive and negative ions network systematically arranged

Coulombic

 

NaCl, KCl, CaO, MgO, LiF, ZnS, BaSO4 and K2SO4 etc.

Hard but brittle

High (≃1000K)

High (≃2000K)

Conductor

(in molten state and in aqueous solution)

Covalent

Atoms connected in covalent bonds

Electron sharing

 

SiO2 (Quartz),

SiC, C (diamond),

C(graphite) etc.

Hard

Hard

Hard

Very high (≃4000K)

Very high

(≃5000K)

Insulator except graphite

Molecular

Polar or non-polar  molecules

(i) Molecular interactions (intermolecu-lar forces)

(ii) Hydrogen bonding

 

I2,S8, P4, CO2, CH4, CCl4 etc.

 

Starch, sucrose, water, dry ice or drycold (solid CO2) etc.

Soft

 

 

Soft

Low

(≃300K to 600K)

 

Low

(≃400K)

Low

(≃ 450 to 800 K)

 

 

Low

(≃373K to 500K)

Insulator

 

 

Insulator

Metallic

Cations in a sea of electrons

 

Metallic

 

Sodium , Au,  Cu, magnesium, metals and alloys

Ductile malleable

High

(≃800K to 1000 K)

High

(≃1500K to 2000K)

Conductor

Atomic

Atoms

London dispersion force

Noble gases

Soft

Very low

Very low

Poor thermal and electrical conductors

Get practice papers FREE

BOOK A FREE TRIAL
Copyright © 2010-2011 www.emedicalprep.com. All rights reserved.
Skip to toolbar