Concept:According to the Kinetic Molecular Theory, the absolute temperature of a gas is directly proportional to the average translational kinetic energy of its molecules.
Formula:$$ K.E_{avg} \propto T \quad \text{or} \quad K.E = \frac{3}{2}kT $$
Solution:- Heat flow is a macro-scale phenomenon driven by a difference in temperature.
- On a molecular level, a higher temperature means the molecules possess a higher average translational kinetic energy.
- When a hotter gas mixes with a colder gas, faster-moving molecules collide with slower-moving molecules, transferring kinetic energy.
- This thermal energy transfer continues until both systems reach thermal equilibrium (equal temperature), meaning they must have identical average translational kinetic energies.
Why other options are incorrect:- Options B & D: While rotational and vibrational energies exist in polyatomic molecules, temperature (and thus heat flow) is strictly defined by average translational motion.
- Option C: Gases are modeled as having negligible potential energy.
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