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Model Theoretical Context
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Physical Atomic Simulation
Billiard Ball Model Assumptions:
• Matter is composed of tiny, solid particles.
• Atoms are indivisible, indestructible spheres.
• No interior subatomic charge exists.
Gold Foil Apparatus
In 1911, Rutherford fired positive alpha particles (He²⁺, charge +2) at ultra-thin gold foil. He expected them all to pass straight through. Instead, some bounced backward, revealing a tiny, incredibly dense positive Gold nucleus (Au, Z = 79).
Apparatus Vacuum Chamber
Observation SandboxCoulomb repulsion physics: Positive alpha particles get repelled by the heavy positive Gold nuclei (Z = 79). Watch how particles approaching closer suffer extreme deflection, whereas most pass untouched.
Spectral Bohr Transitions
Bohr proposed that electrons move in quantized energy orbits (n). To jump up (n_low to n_high), an electron must absorb a photon of exact matching frequency. When falling back down, it emits a colorful photon of that exact wavelength.
Tip: Click the lasers! Resonant photons actively track and seek the rotating electron, colliding cleanly to trigger quantum shell jumps. Non-resonant photons fly straight past!
Atomic Absorption Chamber
Bohr planetary viewRydberg Energy Levels:
• Shell n=1 (Ground): -13.6 eV
• Shell n=2 (1st Exc.): -3.40 eV
• Shell n=3 (2nd Exc.): -1.51 eV
• Shell n=4 (3rd Exc.): -0.85 eV
Hydrogen Spectral Lines: Transitions ending in n = 1 emit UV light (Lyman Series). Transitions ending in n = 2 emit beautiful visible light wavelengths (Balmer Series). Try dropping n = 4 to n = 2!
Probability Cloud Lab
In quantum mechanics, electrons do not orbit in fixed circles. Schrödinger proved they sit in 3D wave probability clouds (Ψ²). We only know where they are when we measure them.
Heisenberg Detection Chamber
Probability SandboxActive Wave Function (Ψ²):
1s spherical orbital
Each point represents a recorded electron impact.
The Uncertainty Principle: Clicking "Observation" measures the exact coordinate of the electron. Over many cycles, you can see how the probability distribution naturally matches the wave equations!
Atomic Concepts Timeline
Lesson Chapter
Atomic Concepts Quiz
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