Class 12 Chemistry Chapter 1 notes – The Solid State

The Solid State is an indispensable chapter that helps to understand the basics of Chemistry. It focuses on Chemistry's State of Matter. The state of matter is the foundation for many chapters to come. The Class 12 Chemistry board exam requires that students fully understand Chapter 1. Students can refer to the Class 12th Chemistry Chapter 1 notes. These are prepared by Chemistry teachers who are well-versed in the CBSE syllabus.

Solid-state Class 12 Chapter 1 Chemistry notes are concise and easy to read. These notes are very reliable and useful as they have been prepared by analysing past years' Class12 Chemistry papers. 

Class 12 Chemistry Chapter 1 notes – The Solid State 

• Solids are substances with a fixed shape and volume. They are marked by rigidity and incompressibility, slow dissemination, mechanical strength, and slow diffusion. They can be classified into: 
• (a) Crystalline solids 
• (b) Amorphous solids 
• The crystalline solids can be further classified as: 
• (a) Metallic solids 
• (b) Ionic materials 
• (c) Solids covalent 
• (d) Molecular solids 
• Space lattices or crystal lattices refer to a regular three-dimensional arrangement of points in space. Only 14 three-dimensional lattices have been identified as Bravais Lattices. The fundamental difference between the Bravais lattices is the angles between faces and relative proportions of the sides. 
• A unit cell refers to the smallest unit of a crystal that, when repeated repeatedly, gives the crystal of the substance.
•  There are three types based on the cube: These are: 
• (a) Primitive cube or simple cube that has one component at each comer. 
• (b) A body-centred cube, in which one constituent is at the center of the cube and one at each comer. 
• (c) Face centred cube, where one constituent is at the centre of each face, and one at every comer. 
• The atoms of pure metal are in the solid crystalline form. There are many ways to pack identical spheres. 
• The number of the nearest neighbors of an atom or ion is known as its coordination numbers.  
• About 74 percent of available space in the hcp/ccp structures is occupied with the spheres. The spheres take up about 68% of the space in a bcc setup. Simple cubic structures have 52.4 percent occupied by spheres. 
• Imperfection and defects refer to any deviation from the perfect arrangement of atoms in crystals. These can be of two types: 
• (a) Point defects 
• (b) Line defects 
• Schottky defects occur when an opposite pair of ions, cations or anions, are absent from the ideal crystal. A large number of Schottky defects can lower the crystal's density, e.g. AgBr. 
• Interstitials refer to atoms orions that are found in the interstitial areas of a crystal. It causes an increase in the density of crystal. 
• Frenkel defects can be described as a combination schottky and interstitials. It is when an ion leaves the crystal's lattice to occupy an interstitial spot. 
• Non-stoichiometric imperfections are large numbers of inorganic substances in which the ratio between the number atoms one type and the number atoms the other kind is not equal to the ideal whole quantity ratio. These compounds are called nonstoichiometric compound. 
• Crystal lattices with excess metal ions in non-stoichiometric compounds have vacant anion site. These anion sites can be occupied by electrons. F-centres are the names given to these anion sites. 
• Solids are classified according to their electrical conductivity. 
• Conductors 
• Insulators 
• Semi conductors 
• The term intrinsic semiconductors is used to describe pure substances with conducting properties like silicon and germanium.  
• They behave differently when solid substances are placed under a magnetic field. They are classified according to their reaction to the magnetic field. 
• (a) Diamagnetic materials: 
• (i) These materials are weakly repelled by a magnet field. 
• (ii). The electrons are paired. 
• (b) Paramagnetic materials: 
• (i) These materials are weakly attracted to the magnetic field. 
• (ii). These substances exhibit permanent magnetic dipoles as a result of the presence unpaired electrons in atoms or molecules.