Period+2+Group+6

Response to Investigation 6 Essential Question(s)**
 * Period 2 Group 6

I now know that water vapor is in the air and how it got there because in class we conducted a "what's in the air lab." In the lab we set up two cups. One had just ice, it was our controlled cup. We also had another cup with ice and water. In the cup with ice and water we added green food dye so we could tell the difference from the water vapor in the air or if it was coming from inside the cup. Each cup had a thermometer in it to get the starting temperature and when water vapor was forming on the outside of the cup. The cup that had the dye was then covered with wrap so that we wouldn't let any water out into the air. Once our experiment was ready then we watched it until little drops of water formed on the outside of the cup. After observing we found out that there is water vapor in the air. We know this because on the outside of the cup with dye inside clear water droplets formed on the outside. It looked like the cup was sweating but that is just a myth. The water wasn't coming from inside of the cup, it came from the outside. We found out that there is always water vapor in the air but it is invisible water in the form of gas until it condenses on to a surface. We saw water droplets on the outside of the cup, the cup was covered so we knew it didn't come from inside the cup. We know that the cup was cooler then the surrounding air. The air around the cup had more molecular motion. Heat transfer is always hot to cold so the faster moving molecules attached themselves to the cooler cup and then gave off energy to the cup. It then condensed to visible water droplets of water. We know that water vapor is in the air because of evaporation. A main energy source, such as the sun, gives energy to water and the molecules start to move faster and collide and then rise into the air as water vapor, which is the process of evaporation. Many of the water droplets had to come together to make one drop because they are so small.

I now know that humidity is the amount of water vapor in the air. Humidity is measured with a hygrometer in the unit of percent. Dew point is the temperature at which air is saturated and condensation occurs, which is at 100%. I know this because of the "Dragons Breath" article. Humidity is the amount of water vapor in the air. There can be a lot of water vapor or a little bit of water vapor in the air. Water vapor is invisible and is in a gas form. It is measured by a hygrometer in percent. Dew point is the temperature at which a volume of air is saturated. Plus, dew point is a certain temperature at which dew begins to form and water vapor changes to liquid form. Dew point varies depending where you are in the world. When a temperature drops below the dew point, water vapor can condense onto a colder surface. When dew point is reached clouds can begin to form. Dew point is measured in degrees of temperature.

Clouds form when the main energy source, the sun, starts to gives its energy to water which makes the water evaporate. I know this because we did an experiment called the clouds and precipitation lab. In the experiment we made a cloud in a bottle. The experiment didn't show us how clouds in the sky were made but how adding pressure and adding air caused the temperature to affect the making of the cloud. Once the main energy source, the sun, gives energy to the water the water molecules then start to move faster and collide more often. The water that gained more molecular motion starts to evaporate into the air. As it rises the temperature drops and there is less pressure as it rises higher into the atmosphere. For clouds to form the temperature must drop down to the dew point. Plus, the air must become completely saturated. The water vapor that is in the air condenses on to condensation nuclei, such as smoke, dust, and other microscopic particles. Condensation nuclei must join together to create a cloud.

Dew is a thin layer of tiny drops of water. I know this because of the article "Dragons Breath." In the article we learned that dew forms on large surfaces and when the air reaches dew point then the water will condense on grass, leaves, and windows as dew. When water vapor is able to condense,it needs a surface to condense onto, specifically a surface that is colder than the dew. Dew forms when a surface cools to a temperature which is colder than the dew point of the air next to the surface. Dew is made of liquid water that has condensed from some of the water vapor contained in the air. = =