The temperature at which the RMS speed of atoms in neon gas is equal to the RMS speed of hydrogen molecules at \(15^{\circ} \text{C}\) is:
(the atomic mass of neon \(=20.2~\text u,\) molecular mass of hydrogen \(=2~\text u\))
1. \(2.9\times10^{3}~\text K\)
2. \(2.9~\text K\)
3. \(0.15\times10^{3}~\text K\)
4. \(0.29\times10^{3}~\text K\)
| 1. | All vessels contain an unequal number of respective molecules. |
| 2. | The root mean square speed of molecules is the same in all three cases. |
| 3. | The root mean square speed of helium is the largest. |
| 4. | The root mean square speed of sulfur hexafluoride is the largest. |
At what temperature will the \(\text{rms}\) speed of oxygen molecules become just sufficient for escaping from the earth's atmosphere?
(Given: Mass of oxygen molecule \((m)= 2.76\times 10^{-26}~\text{kg}\), Boltzmann's constant \(k_B= 1.38\times10^{-23}~\text{J K}^{-1}\))
1. \(2.508\times 10^{4}~\text{K}\)
2. \(8.360\times 10^{4}~\text{K}\)
3. \(5.016\times 10^{4}~\text{K}\)
4. \(1.254\times 10^{4}~\text{K}\)
| 1. | \(\dfrac{400}{\sqrt{3}}\) | 2. | \(\dfrac{100\sqrt{2}}{3}\) |
| 3. | \(\dfrac{100}{3}\) | 4. | \(100\sqrt{2}\) |