Assertion (A) : In rutherford's gold foil experiment, very few `alpha` particle are deflected back
Reason (R ) : Nuclear present inside the atom is heavy

Options

A. If both (A) and (R ) correct and (R ) is the correct explanation for (A)
B. If both (A) and (R ) correct and (R ) is not the correct explanation for (A)
C. If (A) is correct but (R ) is incorrect
D. If both (A) and (R ) are incorrect

Explanation

**Step-by-Step Solution:**

1. **Understanding the Assertion (A)**: The assertion states that in Rutherford's gold foil experiment, very few alpha particles are deflected back. This refers to the observation made during the experiment where most alpha particles passed through the gold foil with little to no deflection, while only a small fraction were deflected at large angles or bounced back.

2. **Understanding the Reason (R)**: The reason given is that the nucleus present inside the atom is heavy. This is a true statement; the nucleus contains protons and neutrons, which are relatively heavy compared to electrons. However, the weight of the nucleus alone does not explain the behavior of the alpha particles during the experiment.

3. **Analyzing the Experiment**: In Rutherford's experiment, alpha particles were directed at a thin foil of gold. Most of the particles passed through, and only a few were deflected back. This was due to the small size of the nucleus compared to the overall size of the atom. The nucleus is dense and positively charged, which causes the deflection of the alpha particles, but the small size of the nucleus means that only a few particles come close enough to be significantly affected.

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