Notes On Classification Of Matter - CBSE Class 11 Chemistry
Chemistry is the branch of science that deals with the study of the composition, structure, properties of matter and changes it undergoes. Anything that has mass and occupies space is known as matter. Matter can exist in three physical states based on the arrangement of constituent particles. Solids Liquids Gaseous In solid state, the particles are held very close to each other in an orderly fashion. Hence, there is not much freedom of movement. Solids have definite volume and definite shape. In liquid state, the particles are loosely held together, and can therefore, move around. Liquids have definite volume but no definite shape. They take the shape of the container in which they are placed. In gaseous state, the particles are far apart as compared to those present in liquid state. Therefore, movement of particles in gases is easy and fast. Gases have neither definite volume nor definite shape, occupies the available space of the container in which they placed. Matter can be classified into pure substances and mixtures based on the chemical composition. Substances which contain only one kind of atoms or molecules are called pure substances. Pure substances can be classified into elements and compounds based on the possibility to separate the substance into its constituents. When elements or compounds are mixed together in any proportion, results in the formation of a mixture. Ex: Ammonia, water…etc. Based on the uniformity of the particles, mixture can further be classified as homogeneous and heterogeneous mixture. If the particles are distributed uniformly throughout the solution, then it is a homogeneous mixture. If the particles are not distributed uniformly throughout the solution, then it is a heterogeneous mixture.

#### Summary

Chemistry is the branch of science that deals with the study of the composition, structure, properties of matter and changes it undergoes. Anything that has mass and occupies space is known as matter. Matter can exist in three physical states based on the arrangement of constituent particles. Solids Liquids Gaseous In solid state, the particles are held very close to each other in an orderly fashion. Hence, there is not much freedom of movement. Solids have definite volume and definite shape. In liquid state, the particles are loosely held together, and can therefore, move around. Liquids have definite volume but no definite shape. They take the shape of the container in which they are placed. In gaseous state, the particles are far apart as compared to those present in liquid state. Therefore, movement of particles in gases is easy and fast. Gases have neither definite volume nor definite shape, occupies the available space of the container in which they placed. Matter can be classified into pure substances and mixtures based on the chemical composition. Substances which contain only one kind of atoms or molecules are called pure substances. Pure substances can be classified into elements and compounds based on the possibility to separate the substance into its constituents. When elements or compounds are mixed together in any proportion, results in the formation of a mixture. Ex: Ammonia, water…etc. Based on the uniformity of the particles, mixture can further be classified as homogeneous and heterogeneous mixture. If the particles are distributed uniformly throughout the solution, then it is a homogeneous mixture. If the particles are not distributed uniformly throughout the solution, then it is a heterogeneous mixture.

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