Language is an important tool in the instructional process. Students must be able to comprehend or form an understanding of the terminology used in a lesson. Science has very specific vocabulary used to explain and define concepts. Before I present a topic for instruction, I choose the vocabulary I intend to use in my lessons. Then, I choose how I intend to define the vocabulary for the purposes of my class. For the purposes of WATER, WEATHER, AND THE WORLD, I have chosen the following key vocabulary words to be taught and used throughout the lessons of this thematic unit. I have included definitions and possible methods for teaching the meanings or concepts represented by the vocabulary.
Water has three FORMS. The most common form is LIQUID which we use to bathe, swim, and drink. When water freezes, it becomes a SOLID or ice and snow. When water boils on the stove, it becomes a GAS or water vapor which becomes part of the air. (Ardley, 1991)
When water changes from a liquid to a gas or seemingly disappears or dries up, it is called EVAPORATION. This can be illustrated in our everyday life by discussing how clothes dry on the clothesline outside. The students will conduct the following experiment from THE SCIENCE BOOK OF WATER to illustrate evaporation. The students will place one-third cup of water in a glass and a saucer. The students will cover the glass with a bowl to trap the water. The saucer will be left on the table, exposed to the air. After many hours, the water in the saucer will disappear. The water changed to water vapor and was carried away by the air. The water in the glass was not exposed to air and did not have a chance to escape.
When water changes from a gas to a liquid, it is called CONDENSATION. In other words, water seems to appear from nowhere like magic. This occurs when water vapor cools and forms little droplets of water. This concept will be illustrated with an experiment from THE SCIENCE BOOK OF WATER. First, place some ice cubes in a dishtowel and crush them with a rolling pin. Then, pour the crushed ice into a glass. Cover the glass with a square piece of cardboard and wait for several minutes. The sides of the glass will become wet with tiny droplets of water because the air cannot hold as much water vapor when it cools than it does when it is warm.
POLLUTION occurs when water is dirtied with trash, human-made solvents or certain chemicals, and other waste products. Living things such as animals, humans, and plants need clean water to grow and stay healthy. Dirty or polluted water makes the living things sick and could ultimately cause death. For example, a polluted pond will no longer be able to support fish and plant life.
Using a simple taste test, the students will differentiate between SALT WATER and FRESH WATER. With this concept, the class will learn the difference between bodies of water. An OCEAN is a salty body of water that separates very large CONTINENTS or bodies of land. A globe will be helpful in clarifying this abstract concept as my class has never visited another continent. PONDS and LAKES are very large pools of freshwater. A RIVER, STREAM, or BROOK are lines of moving fresh water. GROUND WATER is found in an AQUIFER.
CONSERVATION is the act of conserving our resources such as water. In other words, we will look at ways to stop the waste of our water supply. For example, faucets that drip water are a waste. I will link this concept to our mealtime routine of not wasting food. Conservation is especially important during periods of DROUGHT. A drought is a long period of time when there is little to no rain in our environment. A DESERT is a place where there is little to no rain fall all the time. Therefore, the desert has special animals and plants which are able to live with little water. Our ENVIRONMENT is everything that surrounds us. Our weather, land, plants, and water are part of our environment.
The EARTH is the name given to our world, which is one of nine planets to travel around the sun. All nine planets and the sun are called the SOLAR SYSTEM.
EROSION is the effect water has on the way the shore looks. As water crashes objects, rocks, and pebbles onto the shore, the shore slowly changes the way it appears. Rocks become smoother; sand disappears from the shore into the body of water; and caves may form. The size and shape of a river may change due to erosion. The force of the water and pieces of sand it contains brushes against objects like sand paper, creating smoother surfaces and changes in the appearance of the shore.