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所在平台: Udemy |
课程主页: https://www.udemy.com/course/solid-state-chemistry/
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课程名称：固态化学 课程概述：物质存在于三种不同的状态：固态、液态和气态。这三种状态的物质因相互吸引力和分离力的差异而有所不同。固态是具有明确形状、明确体积，且表现出不可压缩性、高刚性和大机械强度等特征的物质。固体可以分为晶体和非晶体。晶体固体具有以下特性：（a）明确的形状或几何图形；（b）长程有序；（c）锐利的熔点。固体被定义为具有刚性、明确形状和体积的物质。与在气体和液体中分子可以自由移动形成流体状态不同，固体中的构成粒子并不自由移动，而是围绕其固定位置振荡。 晶体是具有规则几何形状的固体物质，由原子、离子或分子规则排列形成。晶体固体是指原子、离子或分子规则排列的固体。晶体学是对晶体几何形状和对称性进行研究的学科。晶格是指在三维空间中原子、分子或离子的有序排列。如果用点替代粒子，晶体结构将呈现为点的阵列，称为晶格，而这些点称为晶格点。晶格被称为空间晶格。二维晶格有五种类型：六角形、正方形、矩形、菱形和平行四边形晶格。
Matter exists in three different states like solid, liquid and gas. These three states of matter differ from one another because of the difference in the attractive forces and separating forces.Solids: Solids are the substances which have definite shapes, definite volumes and show non-compressibility, high rigidity, large mechanical strength etc.A solid may be crystalline or amorphous.Crystalline Solids have the following properties:(a) Definite shapes or geometries(b) Long range order(c) Sharp melting pointsDifferent types of Crystal geometries and shapes. A solid is defined as that form of matter which possesses rigidity and hence possesses a definite shape and a definite volume. Unlike gases and liquids in which the molecules are free to move about and hence constitute fluid state, in a solids the constituent particles are not free to move but oscillate about their fixed positions.Crystal. It is a piece of solid substance with a regular geometrical shape caused by a regular arrangement of atoms, ions or molecules making up the solid.Crystalline. The solid which has regular arrangement of atoms, ions or molecules is called crystalline solid.Crystallography. The study of geometry and symmetry of crystal is called crystallography.Lattice. A well-ordered and regular arrangement of atoms, molecules or ions in the three dimensional space is called crystal lattice. If the particles are replaced by points, the crystal structure would be an array of points which is called lattice.These points are called lattice points, and the lattice is called space lattice. There are five types of two dimensional lattices. They are hexagonal, square, rectangular, rhombic and parallelogram lattices.
