Period+7+Group+1

Response to Investigation 6 Essential Question(s)**
 * Period 7 Group 1


 * How can we determine that water vapor is in the air and how does it get there? What is humidity and what is dew point and how are each measured? How do clouds and dew form?**

We can determine water vapor is in the air by condensing it on to an object. We know this because we did a lab called water in the air. What this lab told us was that the water from the cup could not have leaked out on the outside of the cup where we found the water because we colored the water green. How the water vapor gets there is condensation or in other word the water vapor changes back to a liquid state. The air is filled with water vapor, it becomes saturated and the temperature goes down. This turns the water vapor into the water state and it drops onto objects around it i.e salt, and dust, etc.

Humidity is how much water vapor in the air and that it is measured in percents. (%) Using a hygrometer we can read the relative humidity. This is the amount of water vapor in the air compared to how much the air can hold. The Dew Point is the temperature at which water vapor saturates the air. The Dew Point is measured with the dry and wet bulb and a thermometer. It's measured in degrees Celsius. I know this because we had a discussion on dew point. I got this information by reading the article "Dragon's Breath" where it told me about both dew point and humidity. I learned that the dew point is the temperature when the air is saturated. The dew point isn't always the same everywhere and every time. If there's a lot of water vapor in the air, you don't have to lower the temperature much for the the air to be saturated but if there's little water vapor then the temperature would have to decrease a lot more because the colder temperature makes the air more dense and has less room for water vapor.

Clouds form when water vapor condenses onto tiny particles of dust, salt, and other condensation nuclei. Then the air currents will cause those little droplets of water to form into drops which are millions of the droplets together and those drops become clouds. Dew point is the same up till the air rises into the atmosphere then the air cools which saturates it. Then the water vapor condenses onto the nuclei. We learned all of this from the article called "Observing Clouds." So what the droplets of water really do is they get picked up by the condensation nuclei after they evaporate and then ride them until they become to heavy for the condensation nuclei to hold anymore and the fall as rain or snow or an kind of precipitation.

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