Fog is formed when ____________.

Fog forms when moist air cools and water vapor condenses into tiny water droplets suspended in the air. This process is influenced by various factors, which include temperature changes and humidity levels.

When warm air meets cold air, the warm air can cool rapidly, leading to the condensation of water vapor and the formation of fog. This is because warm air holds more moisture than cold air; when the warm air cools, it can no longer retain all of its moisture, resulting in fog.

Additionally, a rapid temperature change can contribute to fog formation, particularly in situations where, for example, a cool breeze moves into a warm, humid area. In such cases, the sudden drop in temperature leads to the cooling of air and subsequent condensation of moisture.

Humidity levels are also crucial in fog formation. When humidity is high, particularly close to 100%, the atmosphere is saturated with moisture. In such conditions, even a slight decrease in temperature can cause the air to become saturated and form fog.

Therefore, all the elements mentioned contribute to the conditions necessary for fog development, making the statement that fog is formed when all these conditions occur accurate. It highlights the interconnectedness of temperature changes, humidity levels, and the interactions between warm and cold air in creating the