In scattering experiment , `alpha` -particles were deflected by

Options

A. Repulsive force of electrons
B. Repulsive force of gold nucleus
C. Attractive force of electrons
D. Attractive force of gold nucleus

Answer

To solve the question regarding the deflection of alpha particles in a scattering experiment, we can break it down into the following steps:

### Step 1: Understand the Nature of Alpha Particles
Alpha particles are the nuclei of helium atoms, consisting of 2 protons and 2 neutrons. They are positively charged due to the presence of protons.

**Hint:** Remember that alpha particles are heavy compared to electrons and consist of protons and neutrons.

### Step 2: Identify the Target Material
In the scattering experiment, alpha particles are directed towards a thin foil of gold. Gold nuclei are also positively charged due to their protons.

**Hint:** Consider the properties of the target material (gold) and its atomic structure.

### Step 3: Analyze the Interaction
When the alpha particles approach the gold nuclei, they experience electrostatic forces. The positive charge of the alpha particles will repel the positive charge of the gold nuclei due to Coulomb's law.

**Hint:** Recall that like charges repel each other, which is crucial for understanding the deflection.

### Step 4: Consider the Mass Difference
The mass of an alpha particle is significantly greater than that of an electron. When an alpha particle collides with a gold nucleus, the momentum change of the alpha particle is significant, while the change in momentum of the gold nucleus is negligible due to its larger mass.

**Hint:** Think about how mass affects the outcome of collisions and the conservation of momentum.

### Step 5: Conclusion on Deflection
The primary reason for the deflection of alpha particles in the experiment is the repulsive force exerted by the gold nuclei. The attractive forces from the electrons surrounding the nucleus are negligible compared to the repulsive force from the nucleus itself.

**Hint:** Focus on the dominant forces at play during the interaction between the alpha particles and the gold nuclei.

### Final Answer
In summary, alpha particles are mainly deflected by the repulsive force of the gold nucleus during the scattering experiment.

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