chemical classification

Pure Substances:-A single substance which can not be separated into other kinds of matter by any physical process is called pure substance.
Pure substances have been classified as elements and compounds.

Elements:- It is the simplest form of a pure substance which can neither be broken nor built .Types of element:-(a)Metals
(b)Non-metals
(c)Metalloids

(a)Metals:-These are solids(exception mercury bc’z it is in liquid form at room temp.)are normally hard.
$ Lusture
 $ high mp & bp
 $ good conductor of heat and electricity.
Ex- Iron, Copper, zinc, gold etc.
(b)Non-metals:-It has opposite property of metals . They are found in all states of matter.
 $No lusture(exception Iodine)
 $poor conductivity of electricity (exception graphite)
 $ Not malleable
Ex- H2,carbon, nitrogen,
sulphur etc.

(c) metalloids:- Both property metals and non-metals.
Ex Arsenic , Antimony, bismuth etc.


Compounds:- These are pure substance that are composed of two or more different elements in fixed proportion of mass . Ex- water, Suger , salt etc. Types of components-
(a)Organic  (b) Inorganic


(a)Organic Compounds:- The compounds obtained from living sources are called organic compounds . Ex- oils, Proteins, Fats, Carbohydrates etc.

(b)Inorganic Compounds:- The compounds obtained from non-living sources such as rock and minerals are called inorganic compounds . Ex- salt, marbles, Fats, washing soda etc.

Mixtures:- A material obtained by mixing two or more substances in any indefinite proportion is called a mixture . Ex- milk, petrol, sea water etc.
Note- The properties of the components in a mixture remain unchanged.

Types of mixture-
(a)Homogeneous Mixture:- It has a uniform composition through out and there are no visible boundaries of separation b/w  constituents. Ex- suger+ water


(b)Heterogeneous  mixture:- It does not have a uniform composition through out and there are  visible boundaries of separation b/w  constituents.
Ex- sand+ water.

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