1. Clouds floating in the sky. How do clouds form in the sky?
Cloud is a visible polymer floating in the air, which is condensed by water droplets or small ice crystals liquefied by water vapor in the atmosphere when it is cold. Clouds are the tangible result of the huge water cycle on the earth. The sun shines on the surface of the earth, and water evaporates to form water vapor. Once the water vapor is supersaturated, water molecules will gather around the dust (condensation nucleus) in the air, and the generated water droplets or ice crystals will scatter sunlight in all directions, thus creating the appearance of clouds. Tens of thousands of tons of clouds can float freely in the air, and there are three key factors. One is because the cloud is in the state of water vapor and its density is smaller than that of air, so the air has strong supporting force to support the cloud to float in the air. Another important factor is the updraft. The updraft of air is also an important reason for supporting clouds to float in the air. The last factor is air resistance. The larger the volume, the greater the air resistance. Although the cloud weighs tens of thousands of tons, its volume is much more terrible than its weight, and it often covers the whole city without pressure, so the air resistance it receives is a very strong supporting force, so the cloud can float freely in the sky.
Second, the causes of various weather. Although clouds have various shapes, their essence is water vapor in the water cycle. When water vapor condenses in the air, it will form small water droplets. As long as the water droplets continue to condense until the updraft can't support the clouds, rainy weather will occur. In winter, because the weather is very cold, water vapor may not condense into water droplets, but directly condense into snowflakes from cold water vapor. Until the updraft couldn't support gravity, so the sky began to snow. ? However, the formation of hail is different from rain and snow. It is a weather in which cumulonimbus clouds meet updrafts. In the sky, for every rise of 100 meter, the temperature will drop a little. If cumulonimbus meets updraft, the strong updraft will send cumulonimbus into the sky, and the supersaturated cumulonimbus will start to condense the Chen Xiaobing block, so it will hail.