CH U3 A1 Atomic History Worksheet.docx - Chemistry Unit 3 Atoms ... - Free Printable

Actually, I can’t solve the problem or explain the solution because you haven’t uploaded an image — and even if you had, I currently cannot view or process images.

However, based on the text you pasted, it looks like you’re working on a Chemistry Unit 6: Acids and Bases assignment involving a “Periodic Table” (though the table shown is actually a list of scientists and their contributions). The task appears to be:

> *“Complete the following summary table with the contributions of each scientist and the atomic theories they were using. Label each type of theory: solid spheres, Plum Pudding, Nuclear Model, Bohr Model, Quantum Mechanical Model.”*

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Here’s how to solve it (based on standard chemistry history):

You need to match each scientist with:
1. Their contribution to atomic theory.
2. The atomic model they are associated with.

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## ✔ Completed Table (with explanations):

| Scientist (Year) | Contribution | Atomic Model |
|-------------------------------|------------------------------------------------------------------------------|--------------------------|
| Democritus (400 BC) | First proposed that matter is made of indivisible particles called "atomos" | Solid Spheres |
| John Dalton (1803) | Developed atomic theory: elements made of atoms; atoms of same element identical | Solid Spheres |
| J.J. Thomson (1897) | Discovered the electron; proposed “Plum Pudding” model (electrons in a positive sphere) | Plum Pudding |
| Ernest Rutherford (1911) | Gold foil experiment → discovered nucleus; proposed nuclear model | Nuclear Model |
| Niels Bohr (1913) | Proposed electrons orbit nucleus in fixed energy levels (planetary model) | Bohr Model |
| Erwin Schrödinger (1926) | Developed quantum mechanical model using wave equations; electrons as probability clouds | Quantum Mechanical Model |

*(Note: The original table includes “Rutherford (1909)” — likely referring to his gold foil experiment published around then. Also, “Schrödinger” is sometimes listed as 1926 for his wave equation.)*

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## 🧠 Bonus: Why these models matter

- Solid Spheres (Dalton): Simplest — atoms as tiny, hard balls.
- Plum Pudding (Thomson): Atoms as positive “pudding” with negative “plums” (electrons).
- Nuclear Model (Rutherford): Tiny, dense, positive nucleus; mostly empty space.
- Bohr Model: Electrons in fixed orbits — explains hydrogen spectrum.
- Quantum Mechanical Model: Electrons exist in orbitals (probability regions) — most accurate modern model.

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## 📝 For the bottom section:

> “Use your chart to determine who is responsible for the following:”

*(Assuming typical questions — fill in names based on above table)*

1. Identified the electron → J.J. Thomson
2. Proposed the nuclear model → Ernest Rutherford
3. Developed the quantum mechanical model → Erwin Schrödinger
4. First to propose atoms as indivisible → Democritus
5. Introduced the idea of fixed electron orbits → Niels Bohr

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✔ If you can type out the exact questions from the bottom of your worksheet (or describe the image), I can give you precise answers!

Let me know if you’d like flashcards, diagrams, or a timeline of atomic models too!