When water molecules gain enough energy they break away from other water molecules completely and become water vapor, water in the gaseous state. This process is known as evaporation.
Water molecules enter the atmosphere where they circulate following wind and rain patterns. As water vapor raises it encounters a drop in temperature. Warmer air can hold more water vapor than colder air so as the vapor rises, more and more water droplets (very small drops of water) start to form. These water droplets aggregate together and form clouds.
Now click on the link to go to the clouds page, which will explore clouds in more detail.
Eventually, the clouds will condense enough that the molecules will form large drops of liquid water (or solid water like snow and ice) that will fall from the sky in the form of precipitation.
Understand the difference between warm and cold air in their ability to hold water vapor and go to the clouds page and learn the different cloud types. Be prepared to answer questions on the information found on these two pages.
