Physics · Class 12
5 free physics experiments and lesson notes for Atoms, with model limits, worked examples and Tamil explanations.
Most alpha particles pass with small deflection; near passes can turn through large angles. A compact positive nucleus explains rare backward scattering. Larger impact parameter or larger incident energy reduces deflection.
Run this experiment →Bohr states have discrete energies and angular momenta. Larger n means a larger radius, lower speed and energy closer to zero. A bound state has negative energy relative to a separated electron and nucleus.
Run this experiment →A spectral line records the energy difference between levels, not the energy of either level alone. Downward transitions emit photons; upward transitions absorb matching photons. A set ending at n2 forms the Balmer series.
Run this experiment →A stronger nuclear charge attracts the same single electron more tightly. At fixed n, radius decreases as1/Z and binding energy magnitude increases as Z². Hydrogen-like means one electron, including charged ions.
Run this experiment →The maximum electron energy sets the short-wavelength cutoff. Target atomic number sets characteristic transitions. Raising tube voltage moves the cutoff without shifting a given target line, once excitation is possible.
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