Basic Concepts of Chemistry

Matter is defined as anything that has mass and occupies space, e.g., water, air, wood, metals, trees, animals etc. Matter can be classified as follows:

A. Physical classification of matter (i.e., solids, liquids and gases)

B. Chemical classification of matter.(i.e. Elements , Compounds and Mixtures)

Element. An element is the simplest form of matter and therefore, can not be split into simpler substances by any chemical or physical method. Elements can be classified as

(a) Metals,          (b) Non-metals and    (c) Metalloids.

Compound. A compound is a pure substance made up of two or more elements combined in a definite proportion. Compounds are homogeneous and have entirely different properties as compared to the individual elements. There are two types of compounds.

Importance of studying chemistry

Chemistry is a subject of great importance because of the significant

contributions it-has made in the diverse fields as illustrated below.

(1)Chemistry in agriculture.

(i) Chemical fertilizers like urea, NPK etc. to improve the crop yield,

(ii) Insecticides and pesticides like D.D.T., B.H.C., methoxychlore etc.

(iii) Preservatives like sodium benzoate, sodium metabisulphate etc.

(2) Chemistry in medicines and healthcare.

(i) Life saving drugs.

(ii) Antibiotics, antiseptics, analgesics, tranquilizers etc.

(iii) Synthetic vitamins and health tonics,

(iv) Better understanding of nutritional requirements.

(3) Chemistry in comfort, pleasures and luxuries.

(i) Commodities of domestic use like soaps, oils, detergents, paints,

plastics etc.

(ii) Synthetic fibers like nylon, rayon, terylene etc.

(iii) Enhancement in comfort through use of chemical compounds like

freon etc. for air conditioning.

(4) Chemistry in industrial applications.

(i) Extraction of elements, making of alloys etc.

(ii) Dyes, paints, pigments, enamels etc.