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Isaac Newton
• He lived from 1642 to 1727.• After seeing an apple fall he new that gravity is the force of attraction exerted by the earth on an object. • He found out that atoms are held together because of forces. -
Period: to
Atom
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Jhon dalton
He lived in gorge street from 1766 to 1844.He developed the first atomic theory. While trying to explain the results of those experiments, Dalton developed the hypothesis that the sizes of the particles making up different gases must be different. -
Micheal faraday
He lived from 1791 to1867
Created the electric motor. He studied the effect of electricity on solutions. -
J. Plucker
He lived from1801 to 1868 He found out that gases had a stable electron configuration.He built a cathode ray tube that was one of the first. -
Dmitri Mendeleef
Lived from 1834 to 1907
He created his own periodic table. He changed the atomic theory by formulating the table of elements by listing them by their atomic weight. -
G.J Stoney
He lived from 1826 to 1911.Introduced the term electron as the fundamental unit of electricity.G.J Stoney contributed to the atom because he came up with the idea of electrons. -
J.J Thomson
Lived from 1856 to 1940 He discovered the electron. Changed the atomic theory because he believed atoms have electrons in them. -
Ruthford
He lived from 1871 to 1937Created a gold foil experiment to find out what the proton is and the nucleus.He said that the atom is mostly empty space. -
Soddy
He lived from 1877 to 1956 He discovered isotopes Frederick Soddy and Rutherford announced their discovery and research on the theory of radioactivity. -
H.G.J Moseley
He lived from 1887 to 1915 He found out that atoms of each element contain a unique. positive charge in their nucleus. His main contributions to science were the quantitative justification of the previously empirical concept of atomic number, and Moseley's law. -
Francis William Aston
He lived from 1877 to 1945
He discovered a large number of isotopes. Discovered existence of isotopes through mass spectrograph. -
Niels Bohr
He lived 1885 to 1962He came up with the Bohr’s model of the atom.His work also led to the theory of different energy levels in atoms that is if an electron drops from a higher to a lower orbit, it must release energy. -
Di Broglie
He lived from 1892 to 1897
His research introduced his theory of electron waves.
In 1924 he said electrons could act as waves under some conditions, this helped scientists understand that the atom didn’t behave like the solar system because electrons do not move in regular orbits. -
James Chadwick
He lived from 1891 1974 In 1932 he discovered the neutron Neutrons help stabilize the protons in the atom's nucleus. -
Enrico Fermi
He lived from 1901 to 1954He discovered the nuclear reactor He won the noble prize in 1938 in physics
