# Is Matter Around us Pure?

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## 7 Types of Pure Substances

Chemistry deals with the study of the structures, physical properties, and chemical properties of material substances. All gases, liquids, and solids are different in terms of their composition. So, the classification of the matter is very important.

Matter is classified into three categories:

• Element
• Compound
• Mixtures

Classification of matter

Elements:

• An element is a substance which cannot be split up into two or more simpler substances by the usual chemical methods of applying heat, light or electric energy.
• An element is a substance which is made of only one kind of atoms.
• There areelements known at present. Hydrogen, helium, carbon, sulphur, aluminium, copper, silver, diamond and graphite are also elements.
• Every substance in this world is made up of one or more of these elements.
• Elements can be in any state of matter: solids, liquids or gases.
• Elements have the same number of protons in their atomic nuclei but they can have different numbers of neutrons and hence different masses.

Isotopes:

• Isotopes are atoms of the same element have different numbers of neutrons.
• elements have been discovered till date, of which the firstare naturally occurring while the remainingare synthetic elements.
• Elements consist of one kind of atoms only and cannot be broken down into simpler fragments and can exist as either atom or as molecules.
• Elements are complete chemical substances and occupy unique positions in the modern periodic table.
• Elements are represented by symbols which are assigned by IUPAC.
• For example, Oxygen is represented by O, Aluminium is represented by Al, etc.
• Examples of some commonly used elements and their chemical symbol:
 Name of the element Chemical symbol Hydrogen $\mathrm{H}$ Boron $\mathrm{B}$ Carbon $\mathrm{C}$ Silicon $\mathrm{Si}$ Sodium $\mathrm{Na}$ Lead $\mathrm{Pb}$ Platinum $\mathrm{Pt}$

#### Separation of mixtures III

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