Passage VII

A material's thermal conductivity is a measure of its ability to transport energy from one location to another. Tables 1 and 2 below list the thermal conductivities (in ; μJ = a unit of energy) of various gases at different temperatures (in °C). Table 3 below lists the masses, in atomic mass units (amu), of the atoms making up the molecules of the gases.

40. A particular gas, CH3X, has a thermal conductivity of 177 at 100℃, Based on the data in Tables 2 and 3, the mass of X is:

Answer and Explanation

Your Answer is

Correct Answer is F

Explanation

From table 2, it can be inferred that the larger the molecular mass, the smaller the thermal conductivity at the same temperature, and the thermal conductivity of CH3X is the largest at 100°C, indicating that the atomic mass of X is smaller than that of Cl, Br, and I atoms quality