Draw the number of scattered particles versus the scattering angle graph for scattering of alpha particles by a thin foil. Write two important conclusions that can be drawn from this plot.
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Rutherford scattering key idea:
Most particles undeflected → empty space
Few large-angle deflections → tiny dense nucleus
Concept: This refers to Rutherford’s alpha-particle scattering experiment. The graph shows how the number of scattered alpha particles varies with scattering angle.
Graph description: Plot:
X-axis → Scattering angle (\( \theta \)) Y-axis → Number of scattered particles Shape of graph:
Very large number of particles at small angles (near \( 0^\circ \)) Rapid decrease as angle increases Very few particles scattered at large angles Extremely small number scattered backward (near \( 180^\circ \)) So, the curve starts high at small angles and falls sharply with increasing angle. Conclusion 1: Atom is mostly empty space. Since most alpha particles pass through with little or no deflection:
Positive charge and mass are not uniformly spread. Most of the atom is empty. Conclusion 2: Presence of a small, dense nucleus. A very small fraction of particles are deflected through large angles:
Indicates strong repulsive force. Positive charge is concentrated in a tiny central region (nucleus). Additional inference (optional):
Nucleus is positively charged and very small compared to atom size.
