Types of Crystals

Types of Crystals:

Crystals are categorized into four types depending upon the nature of the units that occupy the lattice points.

1. Molecular Crystals
2. Covalent Crystals
3. Metallic Crystals
4. Ionic Crystals

1) Molecular Crystals:

The lattice points in molecular crystals comprise of molecules that do not carry any charge. The forces binding the molecules altogether are of two kinds:

(i) Dipole-dipole interaction and
(ii) Vanderwaal’s forces.

Dipole-dipole forces take place in solids that consists of polar molecules example, ice. The Vanderwaal’s forces are more common and take place in all kinds of molecular solids.

2) Covalent Crystals:

The lattice in covalent crystals comprises of atoms connected together by a continuous system of covalent bonds. Diamond is a good illustration for this type.

3) Metallic Crystals:

Metallic crystal comprises of an assemblage of positive ions immersed in a sea of mobile electrons. Therefore, each electron belongs to a number of positive ions and each positive ion belongs to a number of electrons. The force which binds a metal ion to a number of electrons in its sphere of influence is termed as metallic bond. This force of attraction is strong and is therefore responsible for a compact solid structure of metals.

4) Ionic Crystals:

In ionic crystals, the units taking up lattice points are positive and negative ions. Each ion of a specified sign is held by coulombic forces of attraction to all ions of opposite sign. The forces are much strong. The ionic crystals have the characteristics shown below:

a. The heats of vaporization of ionic crystals are very high.
b. The vapor pressure of ionic crystals at normal temperature is very low.
c. The melting and boiling points of ionic crystals are too high.
d. Ionic crystals are brittle and hard.
e. Ionic crystals are insulators in solid state.
f. Ionic crystals are soluble in water and as well in other polar solvents.
g. Ionic solids are good conductors whenever dissolved in water.

 

Latest technology based Chemistry Online Tutoring Assistance

Tutors, at the www.tutorsglobe.com, take pledge to provide full satisfaction and assurance in Solid State homework help via online tutoring. Students are getting 100% satisfaction by online tutors across the globe. Here you can get homework help for Solid State, project ideas and tutorials. We provide email based Solid State homework help. You can join us to ask queries 24x7 with live, experienced and qualified online tutors specialized in Solid State. Through Online Tutoring, you would be able to complete your homework or assignments at your home. Tutors at the TutorsGlobe are committed to provide the best quality online tutoring assistance for Physical-Chemistry Homework Help and assignment help services. They use their experience, as they have solved thousands of the Chemistry assignments, which may help you to solve your complex issues of Solid State. TutorsGlobe assure for the best quality compliance to your homework. Compromise with quality is not in our dictionary. If we feel that we are not able to provide the homework help as per the deadline or given instruction by the student, we refund the money of the student without any delay.

©TutorsGlobe All rights reserved 2022-2023.