At a constant temperature, which of the gases will have the highest average kinetic energy?
A) H2
B) N2
C) O2
D) F2
E) All the gases will have the same average
kinetic energy.

At a constant temperature: E. All the gases will have the same average  kinetic energy.

According to the kinetic-molecular theory, the average kinetic energy of gas molecules (particles) is highly dependent on temperature.

Hence, the average kinetic energy of gas molecules (particles) is directly proportional to the absolute temperature of the gas.

At a constant temperature, all gases would have the same average kinetic energy according to the kinetic-molecular theory of gases.

In conclusion, all the gases would have the same average kinetic energy since the temperature is constant.

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H₂ will have the highest average  kinetic energy

Energy because this motion is expressed as Kinetic energy (KE) which can be formulated as:  

Average velocities of gases can be expressed as root-mean-square averages. (V rms)  

R = gas constant, T = temperature, Mm = molar mass of the gas particles

From the two equations above, it can be concluded

So the highest KE is owned by the gas with the smallest molar mass

Molar mass of the gas :

A) H₂  : 2 g/mol

B) N₂ : 28 g/mol

C) O₂  : 32 g/mol

D) F₂ : 38 g/mol

So H₂ has the highest average  kinetic energy