Key Idea.
Section 1
Rising Air Makes Clouds
Clouds form when warm, moist air rises into the sky. As this air travels upward to higher altitudes, it enters the cold zone of the atmosphere.
The cold temperature forces the invisible water vapor in the rising air to condense. Suddenly, the invisible gas becomes billions of tiny liquid water droplets. A cloud is born.
Section 2
Clouds are Liquid, Not Gas
It is a common mistake to think clouds are made of gas like steam. They are not. Clouds are made of liquid water (or ice).
A cloud is essentially a massive collection of tiny water droplets floating in the sky. If you could walk through a cloud, it would feel wet, just like walking through thick fog. We can see clouds because the liquid droplets reflect sunlight, unlike the invisible vapor that created them.
Section 3
The Role of Particles
For clouds to form, the water needs something to stick to. Tiny specks of dust, salt, or smoke floating in the atmosphere act as surfaces for the water.
When water vapor cools, it condenses onto these tiny specks. Without these microscopic particles in the air, the water droplets would have a hard time forming, and the sky would look very different.
Expand to review the lesson summary and core properties.
Section 1
Rising Air Makes Clouds
Clouds form when warm, moist air rises into the sky. As this air travels upward to higher altitudes, it enters the cold zone of the atmosphere.
The cold temperature forces the invisible water vapor in the rising air to condense. Suddenly, the invisible gas becomes billions of tiny liquid water droplets. A cloud is born.
Section 2
Clouds are Liquid, Not Gas
It is a common mistake to think clouds are made of gas like steam. They are not. Clouds are made of liquid water (or ice).
A cloud is essentially a massive collection of tiny water droplets floating in the sky. If you could walk through a cloud, it would feel wet, just like walking through thick fog. We can see clouds because the liquid droplets reflect sunlight, unlike the invisible vapor that created them.
Section 3
The Role of Particles
For clouds to form, the water needs something to stick to. Tiny specks of dust, salt, or smoke floating in the atmosphere act as surfaces for the water.
When water vapor cools, it condenses onto these tiny specks. Without these microscopic particles in the air, the water droplets would have a hard time forming, and the sky would look very different.