Page 1 :
Subject: Chemistry, Class: IX, Chapter Name: Is Matter Around Us Pure, Chapter Notes, , Top Concepts, , . Anything which has mass and occupies space is called matter, Matter can be classified as pure substances or mixtures, A pure substance may either contain constituent particles of only one, kind or of different kinds. A pure substance has a fixed composition, An element is a basic form of matter which cannot be broken down, into simpler substances by any physical or chemical means, Elements can be broadly classified as metals, non-metals and, metalloids., , . Metals are one category of elements that have lustre. They conduct, heat and electricity. They are sonorous .They are malleable and ductile, Non metals do not have lustre, are not sonorous and are bad, conductors of heat and electricity., , Metalloids are elements having properties intermediate between those, , of metals and non metals, , A compound is a pure substance composed of two or more elements, , chemically combined in a fixed proportion. It can be broken down into, , simpler substances by chemical or electrochemical methods, , .A mixture contains two or more elements or compounds which are, , mixed together in any proportion. In a mixture no new compound is, , formed. A mixture shows the properties of the constituent substances, 11.Mixtures are classified are homogeneous or heterogeneous mixture, 12.Mixtures whose components mix completely with each other to make, , a uniform composition are called homogeneous mixtures, , Downloaded from www.studiestoday.com