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The value closed to the thermal velocity of a Helium atom at room temperature (300K) in ms⁻¹ is - [kB = 1.4 × 10⁻²³ J/K; mHe = 7 × 10⁻²⁷ kg] [JEE-Main On line-2018]
- 1.3 × 10⁴
- 1.3 × 10⁵
- 1.3 × 10²
- 1.3 × 10³
Correct answer: 1.3 × 10³
Solution
The thermal velocity of a gas particle can be calculated using the formula v = sqrt(3kT/m), where k is the Boltzmann constant, T is the temperature, and m is the mass of the particle. Substituting the values for helium at room temperature yields a result close to 1.3 × 10³ ms⁻¹, making this the correct option.
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