Question

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.

Hint:

Rutherford scattering key idea:

Most particles undeflected → empty space
Few large-angle deflections → tiny dense nucleus

Answer 1

Scattering of Alpha Particles: Graph and Conclusions
The scattering of alpha particles by a thin foil (as in Rutherford’s experiment) can be represented by a plot of number of scattered particles versus scattering angle (\( \theta \)). 
Graph:

In the graph: - The y-axis represents the number of alpha particles scattered. - The x-axis represents the scattering angle (\( \theta \)). - Most particles are scattered at very small angles, while very few are scattered at large angles. 
Two Important Conclusions:
1. Most alpha particles pass through undeflected: This indicates that the atom is mostly empty space, allowing most alpha particles to go straight through the foil without any deflection.
2. Some particles are deflected at large angles: A small number of alpha particles experience large-angle deflections, which implies the presence of a very small, dense, positively charged nucleus at the center of the atom that repels the alpha particles.
Summary:
The plot confirms Rutherford’s nuclear model of the atom: atoms consist of a tiny, dense, positively charged nucleus surrounded by electrons, with most of the atom being empty space. The scattering distribution is key evidence for the nuclear structure of the atom.