2. Is Matter Around Us Pure
Introduction to Is Matter Around Us Pure
All the matter around us is not pure. The matter around us is of two types.
In the previous chapter, we have learnt about the three states of matter. Before, understanding the chemical nature of matter, let us first understand the scientific meaning of the term chemical substance
The scientific meaning of the term chemical substance
is different from its everyday meaning. In terms of science, substance is a kind of matter that cannot be separated into other kinds of matter by any physical process
. In other words, substance is a pure form of matter
and not a mixture of several different kinds of matter. Most of the things that we use in our day-to-day life are in the form of mixtures. Pure substances are rare. For example, the dissolved sugar can be separated from its solution by some physical process (evaporation or distillation). However, sugar is itself a substance and cannot be separated by physical processes into its constituents. Similarly, common salt (sodium chloride), iron, mercury, calcium oxide, hydrochloric acid are substance.