In 1803, John Dalton presented a atomic hypothesis based on the results of experiments and observations, and on the basis of this hypothesis, he composed the composition of matter, the rules of chemical coincidence and the physical and chemical changes. The results of many experiments and observations The authenticity of Dalton's nuclear hypothesis was certified and accepted as a scientific theory. Dalton's atomic theory is called Dalton's
Dalton's atomic theory

 According to Dalton's nuclear principle,

 (1) The matter is composed of very subtle (indivisible) particles called atoms.

 (2) Atom is the subtle particle of matter which can not be divided into more subtle particles. The original particle of atomic material is.

(3) Atoms participate in chemical reactions and in chemical reactions the atom is not decomposed or destroyed.

 (4) All atoms of an element are identical to all types, that is, their mass, size and properties are similar.

(5) Each element has a fixed atomic weight. The fundamental property of atomic weight is the fundamental property.

 (6) The atoms of different elements are different from one another and their atomic masses, shapes, etc. are different.

 (7) Nuclear combinations of different elements can be combined into the whole number ratio. | And by combining them, "compound atoms" are formed.
  Elements of atomic   ,      compounds atoms
        A+B                        =        AB
      2A+B                        =        A2B

(8) Nuclear can not be produced and can not be destroyed
Amendments to Dalton's Atomic Principles

In light of modern scientific discoveries and explorations, significant modifications have been made in Dalton's original nuclear principle, which are as follows:

(1) Nuclear is divisible. It is true that atoms are not decomposed into physical and chemical changes, but by extraordinary physical methods the atoms can be broken into smaller particles than them. The atom itself can be used in various types of fine particles Are made from

Those are primary particles or subatomic particles. Elecrons are the main constituents of proton and neutron atoms.

(2) The atoms of an element can be of different atomic masses. Those atoms of an element whose atoms are different, are called isotopes.

(3) Atomic masses of atoms of different elements can be similar. Those atoms of different elements. The atoms of which are equal are called isobars.

(4) The basic symptom of the element is its atomic number and not atomic weight. The number of protons present in the atomic nuclei of an element is called the atomic number, z, of that element. Each element is a fixed Atomic numbers are different. Atomic numbers of different elements are different.

(5) Combinations of atoms are not "compound atoms" but molecules are formed.

(6) The ratio of the combination of atoms is not necessary in the smallest quantities. In the proteins, carbohydrate polymers, etc. the connective ratio of atoms is not in the periphery