1. MATTER Classification of matter Element Metals and non metals Symbols
Molecules
Chemical formula
Compounds
Mixture
Formula unit, Formula mass and Molecular mass

2. CHAPTER NO.2
MATTER
The physical material of the universe is called Matter. OR
Anything having mass and occupies space is called Matter
States of matter
Ordinary matter can exist in three physical states
Solids; Liquids and Gases.
Examples
Silver,Water and Oxygen.

3. Classification of Matter Mixture(Impure Substance)
Compounds
Elements
Homogeneous
Heterogeneous
Metals
Non-metals
Molecular
Compounds
Ionic Compounds

4. PURE SUBSTANCES The substances which are made up of only one
kinds of atoms, ions or molecules are called pure
substances.
Pure substances are further classified into
Element
Compound

5. Element Pure substance having all the atoms with same atomic
number is called an element. Or
A substance consisting of chemically identical atoms is
called an element.
Elements have distinct properties of their own and retain
them under all conditions.
Examples
Gold is an element and if it is broken down into pieces, each
piece will retain the properties of gold, similarly, Iron will
remain Iron and Carbon will remain Carbon after division into
smaller parts.

6. Classification of Elements
Metals
Non-Metals

7. Metals Those elements whose oxides and hydroxides are
basic in nature and possess low I.E., E.N. and E.A. are
called Metals

8. Properties of Metals
They are sonorous, means that they give off a note when hit.
They are malleable and can form sheets.
They are ductile and can be drawn into wires.
They are good conductors of heat and electricity.
They have a relatively high densities.
They have great tensile strength and can withstand stress and strain.
They have high melting point and boiling point.

9. Non-metals
Those elements whose oxides are acidic in nature and possess higher I.E., E.N., and E.A. are called non- metals.
Sulphur Phosphorus

10. Properties of Non-metals
They are non sonorous.
They are neither malleable nor ductile.
They are poor conductor of heat and electricity.
They have relatively low densities.
They are usually brittle and break easily when subjected to stress and strain.
Non-metals have low melting point and boiling point.

11. SYMBOL An abbreviation used for the chemical name of an
element is called symbol. OR
Letter or letters which represent chemical name of an
element is known as symbol.

12. Rules governing symbols of elements
Symbols are composed of one, two or three letters.
If one letter is used, it is capitalized.
If two or three letters are used, the first is capitalized and the others are lowercase letters.

13. Some common elements whose symbols consist of first letter of their English names
Boron
Nitrogen
Fluorine
Sulphur
Carbon
Oxygen
Phosphorus
Iodine B N F S C O P I

14. Some common elements whose symbols consist of two letters of their names
Helium
Bromine
Bismuth
Calcium
Beryllium
Barium
Chlorine
Chromium He Br Bi Ca Be Ba Cl Cr

15. Some common elements whose symbols consist of first and second letters of their Latin names
English Name
Latin Name
Symbol
Potassium
Iron
Copper
Silver
Tin
Antimony
Tungsten
Gold
Mercury
Lead
Kalium
Ferrum
Cuprum
Argentums
Stannum
Stibium
Wolfram
Aurum
Hydrargyrum
Plum bum K Fe Cu Ag Sn Sb W Au Hg Pb

16. Molecule The smallest particle of a substance which can exist
independently as a separate unit and shows all the
properties of that substance is called molecule. OR
Atoms of most elements combine with either atoms of the same
element or atoms of other elements to form molecules.
Types of Molecules on bases of number of atoms:
On the bases of number of atoms Molecules may be
Mono atomic.(He,Ne and Ar).
Diatomic. (H2,O2 and Cl).
Triatomic. (H2O,CO2 and H2S).
Polyatomic.(CH4,NH3 and C6H6).

17. Classification of Molecules
Molecules of
Elements
Molecules of
Compounds

18. Molecules of Elements
The molecule which consists of a fixed number of one kind of atom chemically combined together is known as molecules of elements
Oxygen Molecule Water Molecule
Nitrogen Molecule

19. Molecules of Compounds
The molecule consists of a fixed number of different kinds of atoms chemically combined together is known as molecule of compound.
Carbon dioxide Molecule Sulphur dioxide Molecule
Water Molecule

20. CHEMICAL FORMULA The symbolic representation of molecule of a
compound is called chemical formula. OR
The combination of symbols of elements present In a molecule of a substance is called chemical
formula.

21. Examples of Chemical Formula
Oxygen
Hydrogen
Ammonia
Glucose
Water O2 H2
NH3
C6H12O6
H2O

22. Method of writing a Chemical formula
1) Write the correct symbols of ions side by side. 2) Write the positive ions on left hand side and negative ions on right hand side. 3) Write the valency on the right top side of each ions. 4) Write the polyatomic radicals in brackets. 5)Cross the valencies to the lower right of each radicals. 6) if the valencies are equal then donot cross it.

23. Step 4. Mg+2 Cl-1 Step5. Formula =MgCl2 Examples
Write the chemical formula for the molecules of the
following compounds.
1.Magnesium Chloride
Step 1. Magnesium chloride.
Step 2. Mg Cl.
Step 3. Mg Cl-1
Step Mg Cl-1
Step Formula =MgCl2

24. Aluminium sulphate: Step 1. Aluminum sulphate. Step 2. Al SO4

25. Importance of Chemical Formula
Chemical Formula help us to know about:
Elements present in a molecule.
2.Number of atoms of each element present in a molecule.
3. Composition of the molecule.

26. Types of Chemical Formula
Empirical Formula
Molecular Formula
Structural Formula

27. Empirical Formula The chemical formula which shows simplest ratio
between the atoms present in a molecule of a
compound is called Empirical Formula.
Examples
HO is the empirical formula of Hydrogen Peroxide.
CH2O is the empirical formula of Glucose.
CH is the empirical formula of Benzene.
Note: All Ionic compounds are represented by their Empirical Formula.

28. Molecular Formula
The formula which indicates the actual number of atoms in a molecule is called molecular formula. Molecular Formula represents molecular compounds. Example Molecular formula of Benzene is C6H6

29. Structural Formula
Formula which indicates the arrangement of atoms and bonds in molecule is called structural formula.
Angular Water Linear Carbon dioxide

30. Compound Compound is a pure substance which contains only
one type of molecule made up of atoms of more one
element. OR
The pure substance formed by the chemical
combination of two or more atoms of different
element in a fixed mass ratio is known as compound.
Example
when Carbon is burnt in Oxygen, Carbon dioxide is
formed.

31. Types of Compound
Compound
Ionic Compound
Molecular Compound

32. Ionic Compound
The type of Compound which is formed by the chemical combination of a large number of positive and negative ions is called Ionic compounds .Ionic compounds are generally crystalline, like NaCl.

33. Molecular Compound A compound that consists of separate, independent
units or molecules, is called a molecular compound.
Examples
Water (H2O), Carbon dioxide(CO2),Benzene(C6H6) and
Glucose (C6H12O6)

34. Mixture
An impure substance formed by the physical combination of two or more pure or impure substances is called mixture.
A mixture consists of two or more substance which are not chemically combined. The substances in a mixture could be all the elements, all compounds or a combination of elements and compounds.
For Example:- Air is a mixture because it is composed of many gases like Nitrogen, Oxygen, Carbon dioxide and inert gases which are combined physically and are not in a fixed mass ratio.

36. Heterogeneous Mixture
Types of Mixture
Mixture
Homogeneous Mixture
Heterogeneous Mixture

37. Homogeneous Mixtures
Mixtures having uniform composition throughout are called homogeneous mixtures.
Examples
Air, Steel, Salt, Sugar and water solution.

38. Hetrogeneous Mixture
The mixtures which have different composition throughout its mass is called heterogeneous mixture.
Examples
Rocks, Soils and Ice-Cream etc….

39. Differences between Compounds and Mixtures
1. It is a pure substance. 2. It is formed by chemical combination. 3.Its composition Is fixed. 4.The combining substances lose their properties.
1. It is an impure substance.
2. It is formed by Physical combination.
3. Its composition is variable.
4. The combining substances doesn’t lose their properties.
Compound
Mixture

40. Differences between Compounds and Mixtures
5. It can’t be separated by any physical method. 6. Examples: Glucose, Water and Carbon dioxide gas etc…..
5. It can be separated by simple physical method. 6. Examples: Air, Rocks, Sugar solution etc…..

41. Formula Unit
The smallest repeating unit of an ionic compound is called Formula unit.
Example: NaCl indicates a formula unit, it can’t exist independently.
In case of molecular compound, it may or may not exist independently.
Example: H2O, NH3, CH4……. are the formula units exist independently. Here the formula unit and molecules of there compounds are the same.
On the other hand, CH(from C6H6), CH2O(from C6H12O6), NaCl…… can’t exist independently. Therefore, they aren’t called molecules but they are called Empirical Formula.
Formula unit is used for Ionic and Empirical formula is used for Covalent compounds.

42. Benzene molecule C C C C C H H H H H Emperical formula H
Empirical Formula
Emperical formula H
Benzene molecule

43. [NaCl] is the FORMULA UNIT

44. Molecular mass
The sum of atomic masses of all the atoms present in one molecule of a substance is called molecular mass.
Examples
Molecular mass of Benzene C6H6 = 6 × = 78
Molecular mass of Glucose C6H12O6=6× ×16=180
Molecular mass of Carbon dioxide CO2 = 12+ 2×16 = 44
Molecular mass of Water H2O = = 18
Note: The following points are important for finding molecular mass of a substance.
1) Correct chemical formula of the molecule.
2) Number of atoms of each element in a given molecule.
3) Atomic number of all atoms present in a molcule.

45. Formula mass
It is the sum of atomic masses of all the atoms present in a formula unit or E.F Examples 1)Formula mass of Benzene( CH) = =13 2)Formula mass of NaCl = = 58.5