A solid consists of an aggregation of large number of small crystals, these small crystals have defects in them which are called defects in crystals. The defects in crystals are basically irregularities in the arrangement of constituent particles. Types of defects in crystals :- The defects in crystals are of mainly two types:- ( a…
Atomic radius :- Thus, the edge length or side of the cube a and the atomic radius of each particle r are related as a = 2 r r = a / 2 In ∆ EFD, b² = a² + a² = 2a b = √2 a Now in ∆ AFD c² = a² +…
In Crystals, the constituent particles are close packed and leaving the minimum vacant space. In such a situation, the entropy of crystalline material becomes minimum. Let us consider the constituent particles as identical hard spheres and build up three dimensional structure in following three steps – Close Packing in one Dimension :- There is only…
W. H. Miller in 1839 represented the planes of a crystal by a set of three integers h, k and l, called the Miller indices. To obtained the Miller indices for any crystal plane, the ratios of the intercepts made by the unit plane to those made by the given plane or its parallel plane…
Theoretical Density :- Knowing the unit cell dimensions, the theoretical density d of a cubic crystal can be calculated from the equation d = Z M / N V where Z is the number of atoms in the unit cell, M is the molar mass, V is the volume of the unit cell and N…
Crystal Lattice :- If the three dimensional arrangement of constituent particles like atoms, molecules or ions in a crystal is represented diagrammatically, in which each particle is depicted as a point, the arrangement is called crystal lattice. In 1848, Auguste Bravais showed with the help of geometrical calculations that there are 14 possible three dimensional…
Solid state :- Types of Solid :- On the basis of the nature of order present in the arrangement of their constituent particles, Solid or solid state can be classified as Crystalline and Amorphous. Crystalline Solid :- A crystalline solid state usually consists of a large number of small crystals, each of them having a…
Dispersion of light :- Dispersion of light is the phenomenon of splitting of a beam of white light into its 7 constituent colours when passed through a transparent medium like water droplets or Prism . It was discovered by Isaac Newton in 1666 . Newton discovered that light is made up of seven different colours…
Dispersion by a prism :- When white light ( Sun light ) is incident on a glass prism, the emergent light is seen to be consisting of several colours, the phenomenon of splitting of light into several component colours is known as dispersion. The different component colours that appear in sequence are violet, indigo, blue,…
Angle of deviation ( δ ) :- The passes of light through a triangular prism ABC, The angles of incidence and refraction at the first face AB are i₁ and r₁ while the angle of incidence at the second face AC is r₂ and the angle of refraction or emergence i₂ . The angle between…
Equivalent focal length of two lenses :- Let us consider two lenses L₁ ( focal length f₁ ) and L₂ ( focal length f₂ ) are separated by a distance d and P₂ is equivalent lens of both lenses ( focal length f ). Angle of deviation produce by the lenses P, L₁ and L₂…
Let us consider two lenses A anb B of focal length f₁ and f₂ placed in contact with each other. Let the object be placed at a point O beyond the focus of the first lens A. The first lens produces an image at I₁ is real, it serves as a virtual object for the…
