Which of the following statements is false? (A) The amount of water vapor increases with increasing altitude. (B) The lower layers of the atmosphere are dominated by heavier gases and the upper layers by lighter gases. (C) The upper limit of the atmosphere is approximately 10,000 km. (D) 50% of the atmosphere is confined to an altitude of 5.6 km.

Statement (A) is false because water vapor concentration decreases as altitude increases. Most atmospheric moisture originates from surface evaporation and remains trapped within the lower troposphere. As air rises and cools, its capacity to hold moisture drops, causing water to condense and precipitate. Consequently, the higher layers of the atmosphere are extremely dry compared to the humid air found at ground. ANSWER: (A) The amount of water vapor increases with increasing altitude.