-
John Dalton (Atomic Theory)
Matter is made up of indivisible atoms.
All atoms of an element are identical.
Atoms are neither created nor destroyed.
Atoms of different elements have different weights and chemical properties.
Atoms of different elements combine in simple whole numbers to form compounds. -
J.J. Thompson
Found that cathode rays could be deflected by an electric field. -
Ernst Ruthford
Studied absorption of radioactivity. -
Period: to
Rutherford updated Thomson's Raisin Pudding Model of the atom.
Studied the deflection of alpha particles as they were targeted
at thin gold foil sheets. -
H.G.J. Moseley
Studied the frequencies of the x-rays given off by cathode- ray tubes when electrons strike by anode. -
James Chadwick
Proved that neatrons partiles in the nucleus that made up approximately half the mass of an atom, did exist.