Author Archives: Ankush Sharma

Answer :- In case of BCC (body centred cubic) structure coordination number is 8

here is the answer :-

here is the answer:-

In case of ferromagnetic substaces the direction of domains align themselves in the direction of external magnetic field appllied . This leads to the formation of strong magnetic field. This magnetic field persists even on removing the external magnetic field. so the ferromagnmetic substances can be used for making the permanent magnet.

on supply of heat the lattice particles absorb energy and leave the lattice this may lead to the vacancy defect. In this case the density of the lattice decrease as the particles permanently leave the lattice. The lattice may become coloured .

Molar mass M = 2.7 x 10-2 kg mol -1 Edge length of unit cell a = 405 pm = 4.05 x 103 Number of atom per unit cell Z = ? by using the formula lets put the values

Hexagonal close packed lattice has the highest packing efficiency that of 74 % . bcc has 68% and simple cubic 52% packing efficiency .

Solution:- The number of N atoms in CCP (fcc) = 4 per unit cell Number of tetrahedral voids = 2 x number of atoms = 2 x 4 = 8 Atoms of element M occupy 1/3 rd of tetrahedral voids of tetrahedral voids, so number of M atoms = 8 x 1/3 ratio of MContinue reading “A compound is formed by two elements M and N . The element N forms CCP and atoms of M occupy 1/3 rd of tetrahedral voids. What is the formula of the compound ?”

Here is the solution values given:- 0.5 mol

In square close packing a single particle is touched by four particles . Thus the co-ordination number is 4.

(i) At corner :- The particle present at the corner is shared by eight unit cells . hence 1/8 part of the particle is the share of a single unit cell. (ii) At the body centre :- In case of body centre , the particle is present exactly at the centre of unit cell. henceContinue reading “Explain how much portion of an atom located at (i) corner and (ii) body centre of a cubic unit cell part of its neighboring unit cell”

In case of face centred unit cell the particles are present on the corners of the unit cell as well as on the centre of every face. In case of end centred unit cell the particles are present on the corners as well as on the centres of any two opposite faces.

Hexagonal unit cells have two sides equal and two angles right angle , third angle is 120 degrees. The monoclinic unit cells have unequal cell edges and two right angles.

A unit cell is characterised by six parameters :-

The constituent particles (ions , atoms ) of a crystalline solid are denoted by a points . These points are known as the lattice points.

The metallic solids show these kind of characters.

In case of ionic solids , the ions are the units for the conduction of electricity. when they are in solid state the ions are bound to each other by strong electrostatic forces of attraction . But in the molten form the ions are free to move under the applied electric field thus they canContinue reading “Ionic solids conduct electricity in molten state but not in solid state. Explain.”

The covalent (network) solid has these kind of characters. It is insulator and has high forces of attractions due to which it has high melting point.

The solid which has same value for refractive index in all directions , shows isotropic behaviour and such solids are only the amorphus solids. As it is an amorphus solid so it will not show the clean cut due to the presence of rough surface.