Final answer:
The gas particle that travels the fastest is hydrogen (H₂), due to its lowest molecular mass and the principles of kinetic molecular theory and Graham's law of effusion. The correct answer is o H₂.
Step-by-step explanation:
The gas particle that travels the fastest among N₂, Kr, H₂, F₂, and He is determined by its molecular mass and the principles of kinetic molecular theory.
According to Graham's law of effusion, the rate of effusion of a gas is inversely proportional to the square root of its molecular mass (molar mass).
Therefore, a gas with a lower molecular mass will effuse faster than one with a higher molecular mass. Given the options, hydrogen (H₂) has the lowest molar mass of approximately 2.0 g/mol, thus it would travel the fastest as indicated by its ability to effuse four times as rapidly as oxygen (O₂) and also distribute more quickly after a stopcock is opened.