Question

Explain Dalton’s atomic theory (4 postulates)

Answer 1

Hint: Dalton based his theory on two laws: the law of conservation of mass and the law of constant composition. Dalton hypothesized that the law of conservation of mass and the law of definite proportions could be explained using the idea of atoms.

Complete answer:
Dalton's atomic theory was the first complete attempt to describe all matter in terms of atoms and their properties. Dalton based his theory on the law of conservation of mass and the law of constant composition. The four postulates of Dalton’s atomic theory are given below:
1.The first part of his theory states that all matter is made of atoms, which are indivisible. While this is a handy model for some applications, we now know that atoms are far from being solid spheres.
2.The second part of the theory says all atoms of a given element are identical in mass and properties. A sodium atom is different from a carbon atom.
3.The third part says compounds are combinations of two or more different types of atoms. An example of such a compound is table salt. Table salt is a combination of two separate elements with unique physical and chemical properties.
4.The fourth part of the theory states that a chemical reaction is a rearrangement of atoms. He suggested that chemical reactions don’t destroy or create atoms. They merely rearranged the atoms. Parts of the theory had to be modified based on the discovery of subatomic particles and isotopes.

Note: Dalton’s atomic theory is still mostly true, and it forms the framework of modern chemistry. Scientists have even developed the technology to see the world on an atomic level.