Try it Yourself Â». In the example above, the background image is shown in the same place as the text. We want to change the position of the image, so that it does not disturb the text too much. The position of the image is specified by the background-position property:
Given enough time and an average energy less than 100^@C, all the molecules in liquid water will become gas, and evaporate. Condensation is the return of molecules from the gaseous state to the surface of the liquid. For example, an individual water molecule will remain in suspension in the atmosphere. When enough water molecules join together, the molecules will form a rain drop or snow crystal and fall to the earth.
Condensation can actually occur while the temperature is rising, as it does all the time in a cloud. That is, when condensation starts, the temperature rises as a result of the condensation. Condensation occurs when more water vapour is added to the atmosphere than can be kept apart by the atmosphere at its present temperature. Once water vapour is colliding, the air must be able to knock the water vapour molecules apart or, heat is released and we have condensation. Loss of heat comes from the water vapour sticking together, and it takes heat from the air to keep it from sticking. So, when we have a lot of water vapour. air must have that heat or the water sticks together.