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.


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

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

  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).