“Covalent solids are also called atomic solids because they are composed of neutral atoms of the same or of different elements. These atoms are held together by covalent bonds:” When the covalent bonds give joint molecules like diamonds, silicon carbide or aluminium nitride. When atoms join to form the covalent bonds and separate layers are…
The lattice energy is the energy released when one mole of the ionic crystal is formed from the gaseous ions. OR It is also defined as the energy required to break one mole of the solid into isolated ions in the gas phase. Explanation with examples: Solids are composed of atoms, ions or molecules. However,…
Ionic crystals depend upon the structure and the size of their ions. In the structure of NaCl each Na+ ion is surrounded by six chloride ions. The following figure shows how these ions are arranged in the crystal lattice. It is clear that Na+ ion has ten electrons while Cl– has 18 electrons. The size…
Ionic solids are those crystalline solids in which the particles forming the crystal are positively and negatively charged ions, held together by strong electrostatic forces of attraction (ionic bonds). Examples: The crystals of NaCl, KBr etc. are ionic solids. Properties of ionic Solids (1) Physical State: A well-defined geometrical pattern, describe the arrangements of the…
In 1850, a French mathematician August Bravis observed that crystal lattice of substances can be categorized into seven types. These are called Bravis Lattices and their units cells are referred to as Bravis unit cells. A crystal system may be identified by the dimensions of a unit cell along its three edges or axe, a,…
A crystal lattice is defined as an array of points representing atoms, ions or molecules of a crystal, arranged at different sites in three dimensional space. Formation: A crystal may contains atoms, ions or molecules. In crystalline solids, these atoms, ions or molecules are located at definite positions in space. These are represented by points…