Assertion: At absolute zero temperature, vapour pressure, kinetic energy, and heat content of the gas reduce to zero.
Reason: At absolute zero, temperature velocity reduces to zero.

Options

A. (a) If both (`A`) and (`R`) are correct and (`R`) is the correct explanation of (`A`).
B. (b) If both (`A`) and (`R`) are correct, but(`R`) is not the correct explanation of(`A`).
C. (c) If (`A`) is correct, but (`R`) is incorrect.
D. (d) If (`A`) is incorrect, but (`R`) is correct.

Explanation

To solve the assertion-reason question, we will analyze both the assertion and the reason step by step.

### Step 1: Understand the Assertion
The assertion states: "At absolute zero temperature, vapor pressure, kinetic energy, and heat content of the gas reduce to zero."
- At absolute zero (0 Kelvin), the temperature is theoretically the lowest possible temperature.
- According to the kinetic molecular theory, the kinetic energy of gas molecules is directly proportional to the temperature. Therefore, if the temperature is 0 K, the kinetic energy of the gas molecules will also be zero.
- Since kinetic energy is related to the motion of molecules, if there is no kinetic energy, the vapor pressure (which is the result of molecular motion) will also be zero.
- Additionally, the heat content of the gas, which is related to the energy of the molecules, will also be zero at absolute zero.

### Step 2: Understand the Reason
The reason states: "At absolute zero, temperature velocity reduces to zero."
- The term "temperature velocity" seems to refer to the motion of particles, which is indeed related to temperature.
- At absolute zero, the thermal motion of particles comes to a complete stop. Hence, the velocity of the gas molecules reduces to zero.
- This cessation of motion explains why the kinetic energy, vapor pressure, and heat content are all zero.

### Step 3: Conclusion
Both the assertion and the reason are correct. The reason provided explains why the assertion is true. Therefore, we conclude that:

- **Assertion**: True
- **Reason**: True
- **Correct Explanation**: Yes, the reason correctly explains the assertion.

### Final Answer
Both the assertion and the reason are correct, and the reason is the correct explanation of the assertion.

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