When `alpha`-rays hit a thin foil of gold, very few `alpha-`particles are deflected back. What does it prove ?

Explanation

To answer the question regarding the deflection of alpha particles when they hit a thin foil of gold, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Alpha Particles**: Alpha particles are positively charged particles that consist of 2 protons and 2 neutrons. They are relatively heavy compared to electrons.

2. **Experiment Setup**: In the experiment, a beam of alpha particles is directed at a very thin foil of gold. The gold foil is chosen because it is thin enough to allow alpha particles to pass through, but dense enough to observe any deflections.

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