Answer to Question #81817 in General Chemistry for keila

Question

What happens to water as it boils?

Answer 1

When the water is heated, but its boiling point has not yet been reached, small bubbles begin to form in it. Usually they are formed at the bottom of the tank, as they usually heat under the bottom, and there the temperature is higher. The bubbles contain air. This means that when the temperature rises, the air dissolved in it is released from the water. Water evaporates into the bubbles. Bubbles are lighter than the surrounding water and therefore begin to rise in the upper layers. However, here the temperature is even lower than at the bottom. Therefore, the vapor condenses, the bubbles become smaller and heavier, and then go down again. It is not reached the form of it. Usually, they are formed under heat, the temperature is higher. The bubbles contain air. It is released from the water. Water evaporates into the bubbles. Bubbles are lighter than the upper layers. However, here the temperature is even lower than at the bottom. Therefore, the bubbles condense, the bubbles become smaller and heavier, and then go down again. When the boiling point is reached, the bubbles no longer descend, but float to the surface and burst. Steam comes out of them. At this time, it is not the noise that is heard, but the gurgling of a liquid, which indicates that it boils.