As relative humidity increases, the rate of evaporation of water droplets _________________________.

As relative humidity increases, the rate of evaporation of water droplets decreases. This is because evaporation occurs when water molecules at the surface gain enough energy to transition into the vapor phase. When relative humidity is high, there are already many water vapor molecules in the air. This saturation of the air reduces the gradient between the water surface and the air, making it more difficult for additional water molecules to escape from the surface. Consequently, as humidity rises, the concentration of water vapor in the air approaches the concentration needed for evaporation, leading to a decreased rate of evaporation from water droplets. This principle is important for aerial applications of pesticides because it affects the effectiveness of spray applications and the potential for drift. Understanding these dynamics can help ensure optimal conditions for pesticide application.