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Chemistry – Unit 5 Worksheet 1
1. Hydrogen sulfide is composed of two elements: hydrogen and sulfur. In an
experiment, 6.500 g of hydrogen sulfide is fully decomposed into its elements.
a. If 0.384 g of hydrogen is obtained in this experiment, how many grams of
sulfur must be obtained? How do you know this?
b. What fundamental law does this experiment demonstrate?
c. How is this law explained by Dalton’s Atomic Theory?
2. What experimental evidence did JJ Thomson have for each statement?
a. Electrons have negative charge.
b. Atoms of all elements contain electrons.
3. How did the results from Rutherford’s Gold foil experiment differ from his
expectations?
Modeling Chemistry
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U5 gen ws 1 2010
4. What differences would you expect if beryllium foil were used instead of gold foil in
the alpha-particle scattering experiment depicted in class notes?
5. How did Bohr change Rutherford’s model of the atom? What specific research did
he use to support his model?
6. Bohr proposed that electrons occupy energy levels. Why was such a proposal
necessary? In other words, what problems with Rutherford’s model did Bohr’s
energy levels attempt to solve?
7. How does Bohr’s concept of an energy level differ from Schrodinger’s?
Modeling Chemistry
2
U5 gen ws 1 2010