General Knowledge

Classification of Matter

Classification of Matter According to Chemical Composition

» Pure substances

A single substance (or matter) which can not be separated into other kinds of matter by any physical process is called pure substance

  Pure substances have been classified as :
  1. Elements
  2. Compounds

1. Elements

The simplest form of a pure substance which can neither be broken into nor built from simpler substances by ordinary physical and chemical methods is called element.
Elements are further classified into three types :
(i) Metals
(ii) Non-metals
(iii) Metalloids

(i) Metals
Metals are solids (exception mercury which is liquid at room temperature) are normally hard. They have lustre, high melting point and boiling point and also good conductor of electricity and heat. The conductivity of metal decreases with increase in temperature due to vibration of positive ions at their Lattice points.
Examples—Iron, Copper, Silver, Gold, Aluminium, Zinc etc.

(ii) Non-metals
Non-metals are the elements with properties opposite to those of the metals. They are found in all states of matter. They do not possess lustre (exception-iodine). They are poor conductors of electricity (exception- graphite) and they are not malleable and ductile.
Examples—Hydrogen, Carbon, Oxygen, Nitrogen, Sulphur, Phosphorous etc.

(iii) Metalloids
Metalloids are the elements which have common properties of both metals and non-metals.
Examples—Arsenic, Antimony, Bismuth etc.

2. Compounds

Compounds are pure substances that are composed of two or more different elements in fixed proportion by mass. The properties of a compound are entirely different from those of the elements from which it is made.
Example — Water, Sugar, Salt, chloroform, Alcohol, Ether etc.

Compounds are classified into two types :
(i) Organic Compounds
The Compounds obtained from living sources are called organic compounds. The term organic is now applied to hydrocarbons and their derivatives.
Examples — Carbohydrates, Proteins, Oils, Fats etc.

(ii) Inorganic Compounds
The Compounds obtained from non-living sources such as rocks and minerals are called inorganic compounds.
Examples—Common Salt, Marble, Washing Soda etc.