ES2 - Pebbles, Sand & Silt

The Pebbles, Sand, and Silt Module consists of four sequential investigations, each designed to introduce concepts in earth science. The investigations provide experiences that heighten students' awareness of rocks as earth materials and natural resources. They will come to know rocks by many names and in a variety of sizes. Pebbles and sand are the same material, just different sizes.

Investigation 1: First Rocks
Students are introduced to the mineral portion of the planet on which they live. They investigate several kinds of rocks and begin to understand the properties of rocks. Students rub rocks, wash rocks, sort rocks, and describe rocks. They also begin to organize a class rock collection.

Investigation 2: River Rocks
Students investigate a river rock mixture of earth materials of different sizes. They separate the rocks, using a series of three screens to identify five sizes of rocks: large pebbles, small pebbles, large gravel, small gravel, and sand. They add water to a vial of sand to discover silt and clay.

Investigation 3: Using Rocks
Students learn how people use earth materials to construct objects. They make rubbings from sandpaper, sculptures from sand, decorative jewelry from clay, and bricks from clay soil. They go on a schoolyard field trip to look for places where earth materials occur naturally and where people have incorporated earth materials into building materials.

Investigation 4: Soil Explorations
Students put together and take apart soils. They are introduced to humus as an ingredient in soil. Homemade and local soils are compared, using techniques introduced in Investigation 2.

NGSS Standards Addressed

Disciplinary Core Ideas

ESS1.C: The History of Planet Earth
By the end of grade 2. Some events on Earth occur in cycles, like day and night, and others have a beginning and an end, like a volcanic eruption. Some events, like an earthquake, happen very quickly; others, such as the formation of the Grand Canyon, occur very slowly, over a time period much longer than one can observe.
By the end of grade 2. Wind and water can change the shape of the land. The resulting landforms, together with the materials on the land, provide homes for living things.
ESS2.B: Plate Tectonics and Large-Scale System Interactions
By the end of grade 2. Rocks, soils, and sand are present in most areas where plants and animals live. There may also be rivers, streams, lakes, and ponds. Maps show where things are located. One can map the shapes and kinds of land and water in any area.
By the end of grade 2. Water is found in the ocean, rivers, lakes, and ponds. Water exists as solid ice and in liquid form. It carries soil and rocks from one place to another and determines the variety of life forms that can live in a particular location.

Asking Questions and Defining Problems - in K–2 builds on prior experiences and progresses to simple descriptive questions.
  • Ask questions based on observations to find more information about the natural and/or designed world(s).
  • Ask and/or identify questions that can be answered by an investigation.
  • Define a simple problem that can be solved through the development of a new or improved object or tool.
Developing & Using Models - in K–2 builds on prior experiences and progresses to include using and developing models (i.e., diagram, drawing, physical replica, diorama, dramatization, or storyboard) that represent concrete events or design solutions.
  • Distinguish between a model and the actual object, process, and/or events the model represents.
  • Compare models to identify common features and differences.
  • Develop and/or use a model to represent amounts, relationships, relative scales (bigger, smaller), and/or patterns in the natural and designed world(s).
  • Develop a simple model based on evidence to represent a proposed object or tool.
Planning and Carrying Out Investigations - in K–2 builds on prior experiences and progresses to simple investigations, based on fair tests, which provide data to support explanations or design solutions.
  • With guidance, plan and conduct an investigation in collaboration with peers.
  • Plan and conduct an investigation collaboratively to produce data to serve as the basis for evidence to answer a question.
  • Evaluate different ways of observing and/or measuring a phenomenon to determine which way can answer a question.
  • Make observations (firsthand or from media) to collect data that can be used to make comparisons.
  • Make observations (firsthand or from media) and/or measurements of a proposed object or tool or solution to determine if it solves a problem or meets a goal.
  • Make predictions based on prior experiences.
Analyzing and Interpreting Data  in K–2 builds on prior experiences and progresses to collecting, recording, and sharing observations.
  • Record information (observations, thoughts, and ideas).
  • Use and share pictures, drawings, and/or writings of observations.
  • Use observations (firsthand or from media) to describe patterns and/or relationships in the natural and designed world(s) in order to answer scientific questions and solve problems.
  • Compare predictions (based on prior experiences) to what occurred (observable events).
  • Analyze data from tests of an object or tool to determine if it works as intended.
Constructing Explanations and Designing Solutions in K–2 builds on prior experiences and progresses to the use of evidence and ideas in constructing evidence-based accounts of natural phenomenon and designing solutions.
  • Use information from observations (firsthand and from media) to construct an evidence-based account for natural phenomena.
  • Use tools and/or materials to design and/or build a device that solves a specific problem or a solution to a specific problem.
  • Generate and/or compare multiple solutions to a problem.
Obtaining, Evaluating and Communicating Information - in K–2 builds on prior experiences and uses observations and texts to communicate new information.
  • Read grade-appropriate texts and/or use media to obtain scientific and/or technical information to determine patterns in and/or evidence about the natural and designed world(s).
  • Describe how specific images (e.g., a diagram showing how a machine works) support a scientific or engineering idea.
  • Obtain information using various texts, text features (e.g., headings, tables of contents, glossaries, electronic menus, icons), and other media that will be useful in answering a scientific question and/or supporting a scientific claim.
  • Communicate information or design ideas and/or solutions with others in oral and/or written forms using models, drawings, writing, or numbers that provide detail about scientific ideas, practices, and/or design ideas.

Crosscutting Concepts

Patterns Observed patterns in nature guide organization and classification and prompt questions about relationships and causes underlying them.
  • Patterns in the natural and human designed world can be observed, used to describe phenomena, and used as evidence.
Cause and Effect - Events have causes, sometimes simple, sometimes multifaceted. Deciphering causal relationships, and the mechanisms by which they are mediated, is a major activity of science and engineering.
  • Simple tests can be designed to gather evidence to support or refute student ideas about causes.
  • Events have causes that generate observable patterns.
Scale, Proportion, and Quantity In considering phenomena, it is critical to recognize what is relevant at different size, time, and energy scales, and to recognize proportional relationships between different quantities as scales change. 
  • Relative scales allow objects and events to be compared and described (e.g., bigger and smaller; hotter and colder; faster and slower).
  • Standard units are used to measure length.
Energy and Matter in Systems - Tracking energy and matter flows, into, out of, and within systems helps one understand their system’s behavior.
  • Objects may break into smaller pieces and be put together into larger pieces, or change shapes.
Structure and Function - The way an object is shaped or structured determines many of its properties and functions.
  • The shape and stability of structures of natural and designed objects are related to their function(s).
Stability and Change of Systems - For both designed and natural systems, conditions that affect stability and factors that control rates of change are critical elements to consider and understand.
  • Things may change slowly or rapidly.
  • Some things stay the same while other things change.



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