DALTON,S ATOMIC THEORY

The full name of dalton is john dalton.
John dalton was born in 1766 in a poor weaver's family in England. he received his early education from his father and at the village school. Dalton started teaching in the village at the age of 12. In 1793, Dalton left for Manchester to teach physics , chemistry and mathematics in a collage . In 1794, he described colour blindness. In 1808, Dalton present his atomic theory to explain  the properties of matter. Dalton,s atomic theory of matter became one of the foundations of modern chemistry. Dalton was the first to calculate the masses of atoms of several elements .He was died in 1844.

The theory that , all matter is made up of very tiny indivisible particles (atoms)' is called atomic theory of matter dalton,s give this law.
Dalton put forward his atomic theory of matter in the 1808. The various postulates(or assumptions) of dalton,s atomic theory of matter are as follows:-

  1.   All the matter is made up of very small particles called 'atoms'.
  2. Atoms cannot be divided.
  3. Atoms can neither be created nor be destroyed.
  4. Atoms are of  various kinds. there are as many kinds of atoms as  are elements.
  5. All the atoms of a given elements are identical in every respects , having the same mass,  size and chemical properties.
  6. Atoms of different elements differ in mass, size and chemical properties.
  7. Chemical combination between two (or more ) elements consists in the joining together of atoms of these elements to form molecules of compounds.
  8. The 'number' and 'kinds' of atoms in a given compound is fixed.
  9. During chemical combination , atoms of different elements combine in small whole numbers to forms compounds.
  10. Atoms of the same elements can combine in more than one compound.  

law of chemicals combination 

there are three important laws of chemical combination.  these are:-
  1. Law of conservation of mass (or matter),
  2. Law of constant proportions , and
  3. Law of multiple proportions.


1. Law  of conservation of mass:-
In this law tell as Is state that mass neither be  created nor be destroys in any chemical reaction or chemical combinations.

other words 
mass of reactant = mass of product
reactant  = The elements or compounds which is going to participation in reaction is known as reactant.

product = The new elements or compounds formed after the complete of reaction is known as product.

e.g= H2 +O =  H2O
H2+O is a two reactant.
H2O is a product.

prove 
2H2+O = 2H2O
2(1*2)+16*2 = 2[1*2+16]
4+32 = 2[18]
36 = 36 
hence prove that the chemical reaction is combine to law of 
conservation of mass.

2. Law of constant proportion 

This law tells that the every  compound same elements combined together  in a fixed proportion by mass.
e.g:- H2O
       1*2 : 16
        2:16
        1:8 
means that 1g of hydrogen and the 8g oxygen than the water formed  you right it 1*8:than you multiply both side with same number means 8*8 = 8:64 it is the answer you solve any question use this law of constant proportion.

3. Law of multiple proportions.

Law of multiple proportions, statement that when two elements are  combine with each other to form more than one compound the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers. For example, there are five distinct oxides of nitrogen the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers. For example, there are five distinct oxygen in combination with 14 grams of nitrogen are, in increasing order, 8, 16, 24, 32, and 40 grams, or in a ratio of 1, 2, 3, 4, 5. The law was announced (1803) by the English chemist john dalton it is a great scientist  and its confirmation for a wide range of compounds served as the most powerful argument in support of Dalton’s theory that matter consists of indivisible