First and second graders in our classes were introduced to a unit on the water cycle, beginning with a preassessment to see what they already knew. From that activity, we confirmed or introduced students to some of the associated science vocabulary.

The purpose of this assessment was to determine how much conceptual growth we could measure from preassessment to postassessment. Were students beginning to make connections conceptually? Had they mastered the science vocabulary with the terms we were using?

This task calls upon students to describe and/or accurately draw and label their explanations about how rain forms and where it goes. It allows the teacher the opportunity to check for conceptual understanding and connections being made throughout the unit of study. By encouraging students to use science vocabulary to explain events, science literacy is also being developed.

Students were instructed to complete a labeled drawing of a drop of rain coming out of a cloud and show what happens to it after that.

Science
Other water investigations in the unit included dissolving things in water, observing water as an agent of erosion, making it rain indoors, evaporation investigations, and soil investigations in which students observed how easily water passes through or is held by different soil types.

Make water molecules using three sections of an egg carton for each student. Paint two sections with one color and mark them "hydrogen." Paint the remaining section a different color and mark it "oxygen." Connect the three sections together. Mount all of the class molecules inside a giant drop of water (cut large paper in the shape of a drop of water). This helps children conceptualize that there are many molecules of water inside a single drop of water, and when the drop of water evaporates, the molecules move apart from one another to form a gas.

Language Arts
Students can write acrostic poetry and illustrate it with watercolors, using aspects of the water cycle with the key word written vertically down the page.

Movement/Music
As an introduction to this unit of study, all of our grades-one and -two students (200+) gathered in the gymnasium to simulate the water cycle. They listened to environmental music and sounds while pretending to be water falling as gentle rain, collecting in rivers and lakes, evaporating to form clouds and becoming snowfall when the temperature dropped. (For example, they climbed up the cargo nets to simulate evaporation.) Have students simulate different types of clouds forming as conditions are described to them. (For example, when very hot air rises quickly and hits very cold air.)

Open-ended questions that can guide students’ thinking and build their understanding include:

• What are the water molecules doing when they are in a cloud? How do water drops form in a cloud?
• How are they moving when they come out? Where do they go?
• How is water vapor different from water? How are they the same? (physical changes)
• In which direction does precipitation move?
• Where does water go when it hits the ground?
• In which direction does evaporating water move?
• What makes a cloud form? What can you tell me about the temperature? What happens when a cloud gets warmer? colder?
• Where does the earth get the heat energy to make water molecules move? How does that energy get to the earth?
• Where do you get the energy that moves or heats your body?

(Unifying concepts/big ideas and science concepts to be assessed using the Science Exemplars Rubric under the criterion: Science Concepts and Related Content)

Physical Science – Properties of Matter: Students observe the physical properties and characteristics of water as it changes from liquid to gas and back to liquid again. Students use the terms evaporation, vapor, condensation, precipitation and rain appropriately.

Physical Science – Transfer and Transformation of Energy: Students observe that the sun is a major source of energy for changes on the earth.

Life Science – Populations and Ecosystems: Students see that the major source of energy to ecosystems is sunlight.

Earth and Space Science – Earth Structure and System: Students observe that water covers the majority of the earth’s surface and circulates through the atmosphere in what is known as the water cycle.

Earth and Space Science – Solar System: Students see that the sun is the major source of energy for phenomena on the earth’s surface, such as the water cycle.

Scientific Method: Students describe cause-effect relationships with some justification and use observations and prior knowledge. Students observe and explain reactions when variables are controlled (cause and effect).