Chemistry Class Twelve

# Solid State

## Packing Efficiency of Close Packed Structure - 2

### Packing efficiency in Simple Cubic Lattice:

A unit cell of simple cubic lattice contains one atom.

Let the side of a simple cubic lattice is ‘a’ and radius of atom present in it is ‘r’.

Since, edges of atoms touch each other, therefore, a = 2r

Thus,packing efficiency of bcc structure=52.4%

#### Calculation of dimensions of a unit cell: -

Let

The edge of a unit cell is ‘a’.

The density of unit cell is ‘d’

Molar mass of unit cell is ‘M’.

Number of atoms present in unit cell is ‘z’.

Mass of each atoms present in unit cell is ‘m’.

Where, d is density, z is number of atoms present in unit cell, a is length of edge, and NA is Avogadro constant.

Above expression has five parameters, d, z, a, m and NA . By knowing any four of them fifth can be calculated.

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Solid State - Introduction
Solid State - Crystal Lattice
Solid State - Close Packing Structure
Solid State - Efficiency of Close Packing Structure - 1
Solid State - Imperfections in Solids - Crystal Defects
Solid State - Electrical and Magnetic Properties
Solid State - NCERT In Text Solution 1
Solid State - NCERT In Text Solution 2
Solid State - NCERT In Text Solution 3
Solid State - NCERT Exercise Solution (Part 1)
Solid State - NCERT Exercise Solution (Part 2)
Solid State - NCERT Exercise Solution (Part 3)
Solid State - NCERT Exercise Solution (Part 4)
Solid State - NCERT Exercise Solution (Part 5)

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