discovery of dalton

Dalton's Atomic Theory - John Dalton provided a simple theory of matter to provide theoretical justification to the laws of chemical combinations in 1805. The basic postulates of the theory are: All substances are made up of tiny, indivisible particles called atoms. Atoms of the..

In view of new discoveries about atoms, Dalton's atomic theory was modified as given below: * Atom is no longer indivisible as it has a complex structure of sub atomic particles (electrons, protons and neutrons). * Atoms of the same element may posses different r..

Modern Atomic Theory - In view of new discoveries about atoms, Dalton's atomic theory was modified as given below: Atom is no longer indivisible as it has a complex structure of sub atomic particles (electrons, protons and neutrons). Atoms of the same element may posses differen..

Introduction - The evidence of the electrical nature of matter preceeded the first theories about the structure of matter. In 1832, Michael Faraday discovered electrolysis. He gave the first important clue relating electricity to matter and about the electric nature of atoms. Faraday enunciated two..

Structure of Atom - When scientists started exploring matter, they discovered that the smallest particle of an element that maintains its chemical identity through all chemical and physical changes is called and 'atom'. Just how small these atoms are can be made out if you realize that there are ab..

Summary - Dalton had postulated that matter is made up of atoms, which are indivisible. Thomson was the first to suggest a structure for an atom. According to him, an atom is a positively charged sphere of radius=10 - 1 0 m in which the mass and the positive charge of the atom are uniform..