Chapter 1: Introduction to Chemistry
(Part A)
Chemistry
The branch of science which deals with the study of matter,its composition and structure, changes in matter and laws and principles which govern these changes.
Matter
Anything that has mass and occupies space is called matter.For example,gases,air and water etc.
Branches of Chemistry
Some main branches of chemistry are as follows:
1.Physical Chemistry:It deals with the fundamental principles underlying the various chemical phenomena.It is concerned with theories and experiments that describe the behaviour of chemicals
2.Inorganic Chemistry:It is study of all elements and their compounds except the hydrocarbons and their derivatives
3.Organic Chemistry:It is chemistry of hydrocarbons and their derivatives.
4.Analytical Chemistry:It deals with the detection and estimation of elements and compounds.It is concerned primarily with the composition of substances.
5.Industrial Chemistry:It is the branch of chemistry which is related to industrial processes.In other words,the study of properties,uses and their techniques of preparation of industrial products on large scale are studied in industrial chemitry.
6.Bio-Chemistry:It deals with the study of chemical changes that occur in living organisms.
7.Environmental Chemistry:It is the branch of chemistry which deals with the chemicals and other pollutants in the environment resulting directly and indirectly from human activities.
8.Nuclear Chemistry:Nuclear reactions are associated with radioactive substances.Such reactions are carried out in the nuclear reactors.The study of these nuclear changes,their effects and uses is called nuclear chemistry.
Some Basic Definations
1)Element
An element is the simplest form of matter which cannot be broken down into simpler form by chemical means.
2)Compound
A compound is a substance which is obtained by the chemical combination of two or more elements in a definite ratio by mass.It may decompose into the components from which it is formed.
3)Mixture
A material obtained by mixing two or more elements or compounds in any ratio so that the properties of the elements or the compounds forming the mixture do not change at all is called mixture.
Substance:
Any form of matter which is homogeneous and cannot be separated by mechanical methods is called a substance.For example,carbon,water and alcohol is a pure substance.
Classification of Elements
(i)Metal :
Metals are usually solids with shining surfaces and are good conductors of heat and electricity at room temperature.
(ii)Non-metal :
The elements having dull surfaces and bad conductor of heat and electricity are called non-metals.
(iii)Metalloid :
The elements which have the properties of both metals as well as of non-metals are called metalloids.
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