How hot water turns to stream?

Water molecules are held together by hydrogen bonds, which are weak intermolecular forces. When water is heated, the kinetic energy of the molecules increases, causing the hydrogen bonds to vibrate and stretch. As the temperature increases, the hydrogen bonds become weaker and eventually break, allowing the water molecules to move more freely. This transition from liquid to gas is known as vaporization.

Boiling is the process by which water turns into steam at a given pressure. At sea level, water boils at 100 degrees Celsius (212 degrees Fahrenheit). When water is boiling, the vapor pressure of the water is equal to the atmospheric pressure. This means that the water is evaporating so quickly that the water vapor is pushing against the air with the same force that the air is pushing down on the water.

As the water vapor rises into the air, it cools down. This is because the water molecules lose energy to the surrounding air. As the water vapor cools down, it condenses into tiny droplets of liquid water. These droplets are what we see as steam.