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This model this model was the first to show a nucleus, consisting of protons and neutron. Electrons surround the nucleus but are not shown in distinct energy levels.
Rutherford model
This model was developed after J.J. Thompson discovered electrons, a particle smaller than an atom. It shows electrons floating freely in a positive region.
The "Plum Pudding Model" of the atom
Ernest Rutherford discovered that atoms were mostly _________________.
Empty space
In the gold foil experiment, most of the positively charged alpha particles passed through the gold foil, but some were deflected or bounced back. What did we conclude because of this?
Atoms are mostly empty space with a small, dense, positive center
Which scientist proposed the "plum pudding model" of the atom?
J. J. Thomson
Who was the first to propose that matter consist of indivisible particle of matter called atoms?
Democritus
What scientist is best known for his gold foil experiment?
Ernest Rutherford
In the atomic model nicknamed the "plum pudding" model, what do the plums represent?
Electrons
The cathode-ray tube was used to discover the ____ by ____.
electron by Thomson
What are electrons?
subatomic particles that have negative charges
Which scientist is responsible for first stating that all the atoms of a particular element are identical but are different from the atoms of all other elements?
Dalton
What were J. J. Thomson's major contributions to the atomic theory?
Discovered the electron and Proposed the "plum pudding" model of the atom
In Rutherford's famous "Gold Foil" experiment, some particles passed through the foil, some were deflected, and some were bounced straight back. This observation made Rutherford conclude
gold atoms have a solid nucleus
What subatomic particles make up the nucleus of an atom?
Protons and neutrons
Chadwick is credited with discovering which part of the atom?
neutrons
Who established that "electrons move around the nucleus at fixed distances called orbitals or shells"?
Bohr
