Wednesday, June 13, 2012

Pure and impure substances



  


A pure substance is one which is made up of only one kind of molecules.It has definite composition and properties.All elements and compounds are pure substances.Some examples are oxygen,hydrogen,gold,silver,copper,common,salt,pure water ,alum.An impure substance is one which is a mixture of two or more kinds of molecules and has no definite composition and properties.for example air,soil,atones and pebbles in food grains,sugar in water,sand in water,fruit juice etc.

3 comments:

  1. ya but u didnt define it properly...

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  2. what about concrete,oxygen gas,paper, and cigarette smoke?

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  3. I can define a substance as "A part of matter which is under scientific obersation". It can be classified as pure (elements and compounds) and impure (mixtures).

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