本题目来源于试卷: Particulate Nature of Matter B.3 Ideal Gas Model，类别为 IB物理学
[单选题]
Which of the following average properties of the molecules inside piston containing an ideal gas piston stay constant when the piston expands at constant temperature?
I.Intermolecular potential energy.
II.Kinetic energy.
III.Frequency of collisions.
A. $I$ and $II$
B. $I$ and $III$
C. $II$ and $III$
D. $I$, $II$ and $III$
参考答案: A
本题详细解析:
Explanation: The kinetic model of ideal gases assumes that intermolecular forces (and therefore intermolecular potential energy) are negligible, and that the mean kinetic energy of molecules is directly proportional to gas temperature; hence, Properties I and II stay constant during the expansion. Conversely, Property III changes because gas pressure decreases during the expansion, and pressure scales with the frequency of molecular collisions with the walls of the piston.
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