Period+1+group+1

**Response to Investigation 6 Essential Question(s)**
 * Period 1 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 that water vapor is in the air by seeing condensation and clouds forming in the sky. We learned this in an experiment /lab that we did in class. We took a cup of ice water and left it on our desks with plastic wrap over top so no evaporation could occur. By observing it, we watched and saw water condense on the outside of our cup. We proved that it was condensation by applying food coloring to the clear water. We proved this process was condensation and not a leak in the cup. The water vapor in the air condensed to the cup, colder surface, proving that there is water vapor in the air. Water vapor gets in our air by evaporation. We learned this when we did a demonstration with little water and our skin. We put a tiny bit of water on the top of our hands. The liquid water on our hand heated up. As the water molecules gained kinetic energy, they started to separate and evaporate turning from a liquid to a gas. The water, therefore, is in the air just not in liquid form but in gas form. I know this because of the demonstration in class, we dipped our fingers in water and made a circle with it on the top of our hand. Because our hand was a warmer surface, particles of the water’s molecular motion increased due to conduction, meaning more heat. Evaporation occurred and it formed into water vapor,or the gas form of water. It then entered the air putting water vapor in the air.= =Humidity is the amount of water vapor in the air and it is measured in percent. I know this from investigation 1 when we went outside and used the hygrometer. Hygrometers measure relative humidity. Relative humidity is how much water vapor is in the air compared to how much water vapor the air can hold. We learned that if the temperature outside is hot then the air can hold more water vapor than if it's cold outside, because when the air is warm, the air molecules are smaller and move around more, so there is more room in the air for water vapor. We also did a relative humidity lab where we covered two thermometers with muslin. One of the thermometers had wet muslin on it while the other, dry. We then waved both thermometers around for an equal amount of time. After we finished waving the thermometers around, we subtracted the wet end temperature from the dry end temperature. We then used the dry temperature and the difference of the two end temperatures to find the relative humidity.= =Dew point is the temperature when air is saturated. This is when water vapor turns from a gas to a liquid. It is measured in degrees Celsius using a thermometer. I know this because of the Dragon's Breath article.= =Clouds form by radiation, evaporation, and condensation. Dew forms by condensation of water vapor. I know this because of the bottle experiment we did in our class groups. We took an empty soda can and filled partly with water. We then shook the bottle to make the water molecules gain energy. Next we dropped a burning match into the bottle to give the water even more molecular motion. We then squeezed the bottle to make the pressure increase and making the temperature of the water to rise even more. The water then evaporated into the air as water vapor. Once we let go of the squeezed bottle the air temperature in the bottle saturated, reaching dew point and condensed onto the side of the bottle. Same goes for this experiment as the outdoors. The sun radiates its energy to the water on earth, making the heat up and evaporate in to the air. As the air rises into the atmosphere, they lose energy because there is less pressure the hight up in the atmosphere you go. The air will eventually saturate reaching dew point and condense onto dust particals in the air, known as condensation nuclei. The more this happens the bigger the cloud will be, because of all the little condensation nuclei coming together to make one cloud. Dew point forms by water vapor in the air saturating and reaching dew point. The water vapor then condenses onto a surface like grass, coming together forming water droplets on the ground.=