Chemistry Class 11 Chapter 1. Some Basic Concepts of Chemistry | Page 2

Chemistry : Chemistry is the branch of science that deals with the composition , structure and properties of matter . Chemistry is called the science of atoms and molecule
Branches of Chemistry Organic Chemistry -This branch deals with study of carbon compounds especially hydrocarbons and their derivatives . Inorganic Chemistry-This branch deals with the study of compounds of all other elements except carbon . It largely concerns itself with the study of minerals found in the Earth ' s crust . Physical Chemistry-The explanation of fundamental principles governing various chemical phenomena is the main concern of this branch . It is basically concerned with laws and theories of the different branches of chemistry .
Industrial Chemistry-The chemistry involved in industrial processes is studied under this branch . Analytical Chemistry-This branch deals with the qualitative and quantitative analysis of various substances . Biochemistry-This branch deals with the chemical changes going on in the bodies of living organisms ; plants and animals . Nuclear Chemistry-Nuclear reactions , such as nuclear fission , nuclear fusion , transmutation processes etc . are studied under this branch .
PROPERTIES OF MATTER AND THEIR MEASUREMENT — Every substance has unique or characteristic properties . These properties can be classified into two categories –
physical properties and chemical properties .
Physical properties are those properties which can be measured or observed without changing the identity or the composition of the substance . E . g . colour , odour , melting point , boiling point , density etc . The measurement or observation of chemical properties requires a chemical change to occur . e . g . Burning of Mg-ribbon in air
Chemical properties are characteristic reactions of different substances ; these include acidity or basicity , combustibility etc . Many properties of matter such as length , area , volume , etc ., are quantitative in nature . Metric System was based on the decimal system .