The Water Cycle (Victoria Mouwen)
Title: The Water Cycle
Principle(s) Investigated: The main principles that I will be looking at is evaporation (the process by which water is converted from its liquid form to its vapor form and thus transferred from land and water masses to the atmosphere), condensation (the change of the physical state of matter from gaseous phase into liquid phase, and is the reverse of vaporization) and precipitation (when water in any form of liquid or solid water particles that fall from the atmosphere and reach the surface of the Earth). These three stages are a part of the water cycle, which is the continuous movement of water. We will also talk about how water is a non-renewable resource which means that no new water is ever made, we only have a set amount of water on Earth.
Standards : 6th Grade
Energy in the Earth
A) Students know the sun is the major source of energy for phenomena on Earth's surface; it powers winds, ocean currents, and the water cycle.
Investigation and Experimentation
A) Develop a hypothesis.
Materials: Ice, water, glass jar, small glass bowl, food coloring, plastic cup, permanent marker, Water Cycle sheet, notebook, pencil, and markers, computer
Procedure:
Asking Questions: First you want to ask the students if they know what the water cycle is. The water cycle, also known as the hydrologic cycle or H2O cycle, describes the continuous movement of water on, above and below the surface of the Earth. Then you want to ask them if they are familiar with the three components of the water cycle, evaporation, precipitation, and condensation. If not explain that evaporation is the process by which water is converted from its liquid form to its vapor form and thus transferred from land and water masses to the atmosphere. Condensation is the change of the physical state of matter from gaseous phase into liquid phase, and is the reverse of vaporization. Lastly precipitation is when water in any form of liquid or solid water particles that fall from the atmosphere and reach the surface of the Earth. Before they begin the experiment you can show them a picture of the water cycle and remind them that water is in a constant motion that is why we call it a water cycle because it is never ending process.
Experiment: Before the class has begun the teacher will set up three different samples, one for evaporation, condensation and precipitation.
Evaporation- For this sample the teacher will fill a cup with water and draw a line where the water level is. Then the teacher will place the cup outside for a couple hours and then bring it back inside for the experiment. This will represent what happens in the evaporation process, if you leave water outside the suns energy will turn the liquid water into water vapor, therefore there will be less water in the cup.
Condensation- For this sample the teacher will fill a colored water bottle, more visible this way, full of mostly ice and some water. The water bottle will start to form condensation on the outside of the water bottle. You can describe to your class that this happens because the bottle is colder than the air around it. When the air cools it can’t hold as much water, the water must go somewhere and therefore it condenses onto the bottle.
Precipitation- Add hot water into a glass jar, then add food coloring into the water. Put on top the jar opening a small glass bowl filled with ice. The cold bowl causes moisture in the warm air, which is inside the jar to condense and form water droplets. This example is similar to what happens in our atmosphere when it rains. I add food coloring to the water because the process becomes more visible.
The teacher will have the students come up four at a time to look at each sample and to hypothesize to which one is which. They will write down in their science notebook the answers. During this time the students should not be talking about what they are seeing, the idea is to see if the students understand on their own which sample is which.
After all the students have had a chance to look at the three examples we will come back together as a whole class to talk about what we have found. I will ask the students why they formed the hypothesis that they did. What gave away the examples?
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Student prior knowledge: Usually the Water Cycle is taught after the students have learned about weather. Students need to have an understanding of clouds and how and what they formed from (water). They will also need to be familiar with the scientific method because I will be asking the students to form a hypothesis to what each experiment is demonstrating.
Following Lesson: The different layers of the Atmosphere, air pressure.
Explanation:
Many of us think water will always be there for us when we want it. Without water, living things would die. You will die if you go without water for more than a week. Plants will die without water and that would kill all of the animals that eat the plants.
When disasters happen, the first helpful thing that we send is water. In the United States, we have become so used to having water that we don't think about other countries that suffer years and years of drought; where children drink dirty water that makes them sick, and people walk miles just to get that.
We learned from the water cycle that we are using and re-using the same water that has been on earth since the beginning of time. The scary part is that while the water is the same, the amount of clean water has gone down. At some point, if we do not take care of it, we will be left with only contaminated water.
Questions and Answer’s
1) Why is it important for us to know that water is a nonrenewable resource?
a) First of all a non-renewable resource is a natural resource which cannot be produced, grown, generated, or used on a scale which can sustain its consumption rate, once depleted there is no more available for future needs. This is important to know because we only have a set amount of water on Earth and we must make sure that we take care of our supply of it. We must inform our future generation just how important the protection of our water supply is.
2) How was water created?
a) The elements that combine to make water hydrogen and oxygen were found in the dust, gases, and other things that formed Earth. The molten rock, called magma, that made up early Earth contained water. Some of the water was able to escape from the magma and reach the atmosphere. As the Earth gradually cooled off, the water was able to settle on the surface and billions and billions of liters later the oceans were formed.
3) How does water control our climate?
a) The water cycle drives Earth’s climate. The oceans act as planetary air conditioners that cool Earth. Without them, the land would soak up all the Sun’s heat and be too hot. So why don’t the oceans boil? It’s because of evaporation. The Sun warms the oceans just as it does the land, but that heated-up surface water gets carried away in water vapor. A basic law of science is that warm air rises. The air, warmed by the Sun and the heated-up water vapor, moves higher into the atmosphere. The moving air drives weather patterns worldwide, shifting the clouds and bringing wind, rain, drought, and sunny days alike.
Applications to Everyday Life: Water is a valuable resource for all living things on Earth. Every known form of life on earth, from the largest mammals to the smallest microbes, relies on water. Why? Because water is an extraordinarily versatile molecule it's the perfect liquid medium in which to dissolve nutrients for ingestion or wastes for excretion, to transport important chemicals or even be used as one. Water circulates through the land just as it does through the human body, transporting, dissolving, and replenishing nutrients and organic matter, while carrying away waste material. Further in the body, it regulates the activities of fluids, tissues, cells, lymph, blood and glandular secretions. By understanding the water cycle we are able to understand how our own body uses water to help keep us healthy. Water is important to our everyday life because we are surrounded by water at all times, from the water vapor in the air to our own bodies being made up of 75% water. Understanding the cycle of water will help us have a better understanding to why it is so important to us.
Photographs:
Videos:
How the water cycle works http://www.youtube.com/watch?v=YswL4dIDQuk
This is a great one for younger kids http://www.youtube.com/watch?v=gY9HG8zUgOE
References
For my precipitation experiment www.weatherwizkids.com
Water http://en.wikipedia.org/wiki/Water
Water is so Important for Life http://www.kidsgeo.com/geography-for-kids/0132-water-is-important-to-lifer.php
Why is Water Important http://library.thinkquest.org/04apr/00222/cycle.htm