SOME BASIC CONCEPTS OF CHEMISTRY Class 11 Notes

Class 11 Chemistry 

Unit 1: SOME BASIC CONCEPTS OF CHEMISTRY

bUNIT 1

SOME BASIC CONCEPTS OF CHEMISTRY

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. 

The International System of Units (SI)

The International System of Units (in French Le Systeme International d’Unites–

abbreviated as SI) was established by the 11th General Conference on Weights and 

Measures (CGPM from ConferenceGenerale des Poids at Measures). The SI system 

has seven base units