Development of atomic model By Wakil Period: 460 BCE to 370 BCE Democritus Period: 1 CE to 1 CE The End Thank you Period: 1766 to 1844 BCE John dalton Period: 1856 to 1940 J.J Thomson Period: 1871 to 1937 Ernest rutherford Period: 1885 to 1964 Niels bohr Period: 1901 to 1976 Werner heisenberg