Atomic Models Worksheet
Explore the evolution of atomic models from early concepts to modern quantum mechanics with this Grade 9 science worksheet.
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Atomic Models Worksheet
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Read each question carefully and answer to the best of your ability. Show all your work for calculations.
1. Which atomic model proposed that electrons orbit the nucleus in fixed energy levels?
Dalton's Atomic Model
Thomson's Plum Pudding Model
Bohr Model
Rutherford's Nuclear Model
2. The discovery of the electron led to the modification of which atomic model?
Bohr Model
Quantum Mechanical Model
Rutherford's Nuclear Model
Dalton's Atomic Model
1. J.J. Thomson proposed the model, often called the 'plum pudding' model.
2. In the Rutherford model, the atom's positive charge is concentrated in a small, dense region called the .
3. The model describes electrons in terms of probabilities, occupying orbitals rather than fixed orbits.
1. Dalton's atomic theory stated that atoms of the same element are identical in mass and properties.
True
False
2. The Bohr model successfully explained the spectra of multi-electron atoms.
True
False
1. Briefly describe the main contribution of Ernest Rutherford to the atomic model.
2. Explain one limitation of the Bohr model of the atom.
Refer to the Bohr model diagram below to answer the following question.
3. In the Bohr model shown above, what do the concentric circles represent?
Match each scientist with their primary contribution to atomic theory.
1. John Dalton
a. Discovered the electron
2. J.J. Thomson
b. Proposed the plum pudding model
3. Ernest Rutherford
c. Developed the first comprehensive atomic theory
4. Niels Bohr
d. Proposed electrons orbit in fixed energy levels