A : Electrons flow in external circuit of galvanoic cell while ions flow in internal circuit.
R : Direction of current flow is reverse that of electron flow.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1).
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2).
C. If Assertion is true statement but Reason is false, then mark (3).
D. If both Assertion and Reason are false statements, then mark (4).

Answer

To solve the given question, we need to analyze the assertion and reason provided, and determine their truth values as well as the relationship between them.

### Step-by-Step Solution:

1. **Understand the Assertion**:
- The assertion states: "Electrons flow in the external circuit of a galvanic cell while ions flow in the internal circuit."
- In a galvanic cell, oxidation occurs at the anode (where electrons are produced), and these electrons flow through the external circuit to the cathode (where reduction occurs). Meanwhile, ions move through the electrolyte in the internal circuit to balance the charge.
- Therefore, the assertion is **True**.

2. **Understand the Reason**:
- The reason states: "Direction of current flow is reverse that of electron flow."
- By convention, electric current is defined as the flow of positive charge. Since electrons are negatively charged and flow from the anode to the cathode, the current flows in the opposite direction, from the cathode to the anode.
- Thus, the reason is also **True**.

3. **Determine the Relationship**:
- Now, we need to assess whether the reason correctly explains the assertion.
- The assertion is about the flow of electrons and ions in a galvanic cell, while the reason discusses the direction of current flow relative to electron flow. Although both statements are true, the reason does not explain why electrons flow in the external circuit and ions flow in the internal circuit.
- Therefore, the reason is not the correct explanation of the assertion.

4. **Choose the Correct Option**:
- Based on our analysis:
- Both the assertion and the reason are true.
- However, the reason does not correctly explain the assertion.
- Thus, the correct option is **2**: Both assertion and reason are true, but the reason is not the correct explanation of the assertion.

### Final Answer:
**Option 2**: Both assertion and reason are true, but the reason is not the correct explanation of the assertion.

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