Passage VI

For gas atoms in a state of random motion, the mean free path, λ, is the average distance a gas atom will travel between collisions with other gas atoms. This distance depends upon the diameter of the gas atom, d, the volume of the gas, V, and the number of atoms of the gas, N. Table 1 lists the name, symbol, and value of d (in nanometers, nm) for each of 4 gases. Figure 1 shows, for each gas, at 293 kelvins (K), how λ (in nm) varies with V (in liters, L) in a sample with N = 6 x 1023 atoms of the gas. Figure 2 shows, for each gas, at 293 K, how λ varies with N in a sample with V = 25 L.

40. For a particular sample of radon (Rn) gas in a 25 L container at 293 K, λ is approximately 320 nm. If d for Rn is 0.240 nm, then, based on Table 1 and Figure 2, approximately how many Rn atoms are most likely in this sample?

Answer and Explanation

Your Answer is

Correct Answer is F

Explanation

It can be seen from table 1 that d=0.24 nm is longer than the d of all 4 elements in table 1, so it is reflected in figure 2, that is, the Rn line should be at the bottom. Therefore, when the ordinate λ=320 nm, the abscissa should be less than 6