In geiger-marsden scattering experiment , the trajectory traced by `alpha`- particle depends on

Options

A. number of collision
B. number of scattered `alpha`-particles
C. impact parameter
D. none of these

Explanation

To solve the question regarding the trajectory traced by an alpha particle in the Geiger-Marsden scattering experiment, we can follow these steps:

### Step 1: Understand the Geiger-Marsden Experiment
The Geiger-Marsden experiment, also known as the Rutherford gold foil experiment, was conducted to study the scattering of alpha particles by a thin foil of gold. This experiment provided crucial insights into the structure of the atom.

### Step 2: Identify Factors Influencing the Trajectory
The trajectory of an alpha particle as it approaches a nucleus can be influenced by several factors, including:
- The number of collisions
- The number of scattering alpha particles
- The impact parameter
- None of these

### Step 3: Define Impact Parameter
The impact parameter (denoted as B) is defined as the perpendicular distance from the center of the nucleus to the initial velocity vector of the alpha particle. It essentially determines how close the alpha particle will come to the nucleus.

### Step 4: Analyze the Effect of Impact Parameter
- For a small impact parameter (B), the alpha particle approaches the nucleus closely, leading to a stronger electrostatic repulsion due to the positive charge of the nucleus. This results in larger scattering angles.
- Conversely, for a larger impact parameter, the alpha particle will not come as close to the nucleus and will experience less deflection.

### Step 5: Conclusion
From the analysis, it is clear that the trajectory traced by an alpha particle in the Geiger-Marsden scattering experiment heavily depends on the impact parameter. Therefore, the correct answer to the question is that the trajectory depends on the impact parameter.

### Final Answer
The trajectory traced by an alpha particle in the Geiger-Marsden scattering experiment depends on the **impact parameter**.

---