If two gases (A and B) that have detectable odors and the same temperature are released simultaneously on one side of a room, and the odor of Gas A is noticed one minute before that of Gas B, what conclusion can be made?

The observation that the odor of Gas A is detected one minute before the odor of Gas B suggests that Gas A has a lower density than Gas B. Gases with lower density typically diffuse more rapidly than those with higher density. This phenomenon is explained by Graham's law of effusion and diffusion, which states that the rate of effusion or diffusion of a gas is inversely proportional to the square root of its molar mass.

Since Gas A reaches the observer before Gas B, it indicates that Gas A is moving faster through the air. This faster diffusion rate is characteristic of lighter gases, aligning with the conclusion that Gas B, being denser, would diffuse more slowly than Gas A. Therefore, gas A having a higher rate of diffusion, which leads to an earlier detection of its odor, supports the idea that gas B must indeed have a higher density compared to gas A.