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18 terms

LC Chem 1.2 Atomic structure

chemistry
STUDY
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Greeks
Philosophers who first proposed that matter was composed of minute particles
Diffusion
The spreading out of particles through random motion from regions of higher concentration to regions of lower concentration
Dalton
Scientist who proposed the Atomic Theory
Atomic Theory
1. All matter is made up of very small particles called atoms. 2. Atoms are indivisible. 3. Atoms cannot be created or destroyed
Crookes
Scientist who investigated cathode rays in vacuum tubes
Cathode rays
Streams of negatively charged particles called electrons
Properties of cathode rays
1. Form shadows. 2. Cause glass to fluoresce. 3. Cause a paddle wheel to turn. 4. Consist of charged particles.
Stoney
Scientist who named the electron
Thomson
Scientist who showed that electrons are negatively charged and measured the e/m of the electron
Millikan
Scientist who measured the charge on the electron using his Oil Drop experiment
Thomson
Scientist who proposed a simple "plum pudding" model of the atom
Rutherford
Scientist who discovered the nucleus of the atom and the existence of protons in the nucleus.
Expected result
Most of the alpha particles should pass straight through the thin foil. Some alpha particles should suffer slight deflections.
Actual result
Most of the alpha particles went straight through the metal foil. Some of the alpha particles were deflected at large angles. A few were reflected back along their own path.
Chadwick
Scientist who discovered the neutron
Proton
Relative Charge = +1. Relative Mass = 1. Located in the nucleus
Neutron
Relative Charge = 0. Relative Mass = 1. Located in the nucleus
Electron
Relative Charge = -1. Relative Mass = 1/1838. Located outside the nucleus