Average translational KE of a He atom at 300 K is approximately ($k_B = 1.38 \times 10^{-23}$ J/K):
A$6.2 \times 10^{-21}$ J
B$6.2 \times 10^{-23}$ J
C$300 k_B$
D$1$ J
Answer & Solution
Correct answer: A. $6.2 \times 10^{-21}$ J
$\frac{3}{2} k_B T = \frac{3}{2} \times 1.38 \times 10^{-23} \times 300 \approx 6.21 \times 10^{-21}$ J per atom. Same for all monatomic gases at the same temperature.
Related questions
A diatomic ideal gas has $C_v = \tfrac{5}{2}R$. Its $C_p$ and ratio $\gamma$ are:A monatomic ideal gas has degrees of freedom $f = 3$. Its molar specific heat at constant A jar of gas is heated so its absolute temperature doubles. The average kinetic energy perA balloon at STP contains $1$ mol of ideal gas. Using $R = 8.314$ J/(mol K) and $T = 273$ The number of moles of oxygen ($O_2$) gas in a vessel of volume 1 L at STP (273.15 K, 1.01If the mean free path of N₂ at 1 atm is ~80 nm, what is it at 0.01 atm (same T)?Two ideal gases A (monatomic) and B (rigid diatomic) at same T are mixed in equal moles. TThe internal energy of 2 moles of nitrogen gas (rigid diatomic) at 300 K is approximately