Water in nature is constantly changing from one state to another. Thanks to this, the water changes its place. It passes through the air, from the air into the soil, to the plants and back. This movement of water between the ground and the air and the transition from one state to another is called the water cycle. When water is heated by the sun, some of it evaporates and turns into water vapor. The most water evaporates from rivers, seas, oceans and dams. Water vapor rises high into the sky where the air is colder. There, the water vapor cools and liquefies. This is how small water droplets are formed, which collect and turn into clouds. The water in the clouds returns to the ground in the form of rain, snow, hail. We all know that the water in seas and oceans is salty. But then why is the rain not salty? Let's find out! 

For this you need: a glass of water, salt, a spoon, a candle. Pour and stir a teaspoon of salt into a glass of water. It is scooped out of the already salted water with the spoon and heated with the candle. Result: the salt remains on the spoon, and the water has evaporated. Conclusion: Salt is heavier than water. That's why the rain isn't salty!