Palo Alto Unified School District — Science OnLine Guide for Teachers
Water
4th Grade Earth Science Unit |
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General Information
The Water unit is a Full Option Science System (FOSS)
kit created by the
Lawrence Hall of Science at the University of California, Berkeley. It is published by Britannica.
In this unit students are expected to
- Observe and explore properties of water in liquid and solid states
- Observe the expansion and contraction of water as it gains and loses heat
- Investigate factors that influence the cycle of evaporation and
condensation of water
- Compare water quality using indicators
- Observe changes that occur in water that has flowed over limestone
- Acquire the vocabulary associated with water
- Record observations in writing and pictures
- Exercise language, social studies, and math skills in the context of science
- Become aware of the importance of water in their lives
- Gain experiences that contribute to their understanding of several
pervasive themes that point out connections among scientific ideas and
processes: PATTERN, STRUCTURE, INTERACTION, CHANGE, and SYSTEM
Core Concepts
- Water is an Earth material that has identifible characteristics that can be changed and altered in various ways.
- Cold water sinks because it is denser than when it is warm. As it sinks, warm water is pushed up and so appears to rise.
- Water that has evaporated into the air is a gas called water vapor.
- Warm air can hold more vapor than cold air. When warm, humid air cools, some vapor condenses and turns into liquid.
- Much of the water that falls to Earth runs into rivers and streams that return it to the oceans where the cycle begins again.
- Surface tension is a property of water which causes a small quantity of water to pull itself into a sphere, the geometric shape with the smallest surface area.
- Water percolates through Earth materials, which may change the hardness of the water.
Misconceptions
- Clear water is pure water.
- Hard water which leaves a residue when evaporated is not pure and not "good for you."
