An English Chemist, Dalton in 1803 put forward atomic theory, known as Dalton's Atomic Theory according to which all matter is composed of extremely indivisible particles which he named atoms (Greek : atom = cannot be cut i.e., indivisible.)
However his concept of indivisibility of atom did not hold long and it was proved by the experiments made by brilliant research workers like J.J. Thomson (1897), Rutherford (1911), Neils Bohr (1912), Chadwick, Mosely and others that the atom itself has complex structure, i.e., the atom consists of several particles, called sub-atomic particles like electron, proton, neutron, positron, neutrino, meson etc. Out of these, remains indivisible in all physical and chemical changes.
0 Comments