Pourquoi les nuages ne tombent-ils pas?

A cloud is a collection of water droplets that flies over the Earth. Clouds look as light as feathers when you look at them floating in the sky, but in reality they are thousands of tons. All around us, in the air, there is water vapor that is invisible. It is a gas in which there are water molecules that are so small that we cannot see them, but nevertheless they are there, all around us, dispersed in the air. So the clouds are water droplets or ice crystals and together they weigh hundreds of thousands of tons. When the water droplets get bigger, they get heavier and they fall on the ground, it rains! So clouds can fall on our heads when it rains.