Assertion: The centre mass of an electron and proton, when released moves faster towards proton.
Reason: Proton is heavier than electron.

Options

A. (a) If both Assertion and Reason are true and the Reason is correct explanation of the Assertion.
B. (b) If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
C. (c) If Assertion is true, but the Reason is false.
D. (d) If Assertion is false but the Reason is true.

Explanation

To solve the question, we need to analyze the assertion and the reason provided.

### Step 1: Understand the Assertion
The assertion states that the center of mass of an electron and a proton, when released, moves faster towards the proton.

### Step 2: Analyze the Reason
The reason given is that the proton is heavier than the electron. We know that the mass of a proton is approximately 1800 times that of an electron. This means that the proton is indeed much heavier than the electron.

### Step 3: Center of Mass Concept
The center of mass (CM) of a system of particles is a point that represents the average position of the mass distribution. For two particles, the center of mass is calculated using the formula:
\[ R_{CM} = \frac{m_1 r_1 + m_2 r_2}{m_1 + m_2} \]
where \( m_1 \) and \( m_2 \) are the masses of the particles, and \( r_1 \) and \( r_2 \) are their positions.

### Step 4: Determine the Position of the Center of Mass
Since the proton is much heavier than the electron, the center of mass will be closer to the proton. However, the center of mass itself does not move unless an external force acts on the system.

### Step 5: Evaluate the Assertion
The assertion claims that the center of mass moves towards the proton. This is incorrect because the center of mass remains stationary unless acted upon by an external force.

### Step 6: Conclusion
- The assertion is **false**.
- The reason is **true**.

Thus, the correct answer to the question is that the assertion is false, but the reason is true.

### Final Answer
**Assertion: False; Reason: True.**