(A) electron            (B) neutron            (C) proton            (D) atomic number
(E) mass number     (F) isotope             (G) nucleus          (H) Dalton
(I) electron cloud     (J) Thomson          (K) Bohr               (L) Rutherford

____ 1.) center part of an atom; contains almost all of the mass of an atom   G

____ 2.) equal to the number of protons in an atom; whole number on the Periodic Table     D

____ 3.) equal to the number of protons plus the number of neutrons in an atom                E

____ 4.) discovered the electron using a cathode ray tube                   J

____ 5.) atoms of the same element, but have different masses                   F

____ 6.) negatively-charged subatomic particle              A

____ 7.) part of the atom that surrounds the center; accounts for almost all of the volume of an atom       I

____ 8.) discovered the nucleus with the gold foil experiment               L

____ 9.) positively-charged subatomic particle               C

____ 10.) established that atoms of one element are not changed into atoms of another element in a
               chemical reaction          H

____ 11.) hypothesized that electrons travel around the center of the atom in particular paths         K

____ 12.) subatomic particle with no charge                  B

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