Investigation 2 - Impacts of Change in Glacier Ice
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Class Time Required |
Total: 9-11 class periods |
Activity 2B: Melting Ice Activity 2C: Stream Table Activity 2D Transparency/Turbidity: Activity 2E Glacier game: |
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| About 2 hours to read materials, gather supplies, and prepare student materials. | |
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Prior Student Knowledge |
Knowledge of effect of melting sea ice (from Investigation 1), experience or instruction in concept mapping |
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Vocabulary |
ablation, advance, aspect, copepod, crevasse, equilibrium, euphotic, firn, isostatic rebound, recede, retreat, terminus, transparency, turbidity |
| Science GLEs Addressed |
6th Grade: SA1.1, SA1.2, SA3.1, SB1.1, SB3.1, SC1.2, SC3.2, SD2.3, SE2.1, SE2.2 7th Grade: SA1.1, SA1.2, SA3.1, SB1.1, SE2.2 8th Grade: SA1.1, SA1.2, SA2.1, SE 2.2, SE3.1 |
This investigation has been selected as an NSF-funded Climate Literacy and Energy Awareness Network (CLEAN) educational resource.
Overview: In this 9-11 day investigation, students explore ways that changing climate can affect physical and biological conditions in rivers, the ocean, and other aquatic ecosystems. Activity 2A: Changing Landscape asks students to analyze “repeat photographs” (taken from the same vantage point at different times) of Alaska glaciers to observe the effects of retreating glaciers on the landscape. In Activity 2B: Melting Ice, students conduct a simulation to investigate the effect of melting glaciers on sea level. In Activity 2C, Stream Table, students simulate increasing stream flows that result from melting glaciers and observe the effects on the landscape and water quality. In Activity 2D: Transparency/Turbidity students construct a mini Secchi disk to investigate transparency and the effects of increased turbidity from the increased flows as glaciers melt on aquatic and marine ecosystems.
Finally, they play a board game in Activity 2E: Glacier Game to review the effects of retreating glaciers and increasing stream flows and erosion on river, coastal, and ocean ecosystems.
Focus Questions:
What changes occur in a landscape when a glacier melts and recedes?
Does melting glacial ice cause a change in sea level?
Will changes in sea ice or glacial ice cause the most change in sea level?
How do melting glaciers affect stream flows, erosion, and habitats for fish and wildlife?
Activity 2A: Changing Landscape
Focus Question:
What changes occur in a landscape when a glacier melts and recedes?
Engagement: (20-30 minutes)
Review with students the previous activities regarding sea ice. Ask students to think about land ice-glaciers. Offer the opportunity for them to share what they might know about glaciers. Review how glaciers are formed, and how they move. Ask students if they know where the most glacier ice is located in the world. (Most glacier ice is in two places – Greenland and Antarctica. Alaska’s glaciers only make up a small percentage of the world’s glacier ice).
Students should be familiar with the terms “advance” and “retreat.”
Choose one or more of the following sites to share and discuss with students. Choose sites according to your students’ level of ability to read and understand the information.
A nice explanation and photos of glacier topics can be found at Teachers Domain
NOVA Science Now: Video of a moving Jakobshavn glacier in Greenland
How Glaciers Move. Alaska Science Forum, Article #145
Journey to Alaska’s Glaciers: WebQuest to Explore How Glaciers Shape the Land
Exploration: (30 minutes)
Explain to students that they will analyze a variety of glacier photos to observe changes in landscape over time.
You may choose to use photos from these Alaska glacier photos , the five Alaska glaciers illustrated on the Teacher’s Domain site,or choose your own from the National Snow and Ice Data Center Repeat Photography of Glaciers.
Several copies of each photo set may be printed. Students may exchange photos once they have completed their observations.
You may choose to have students work individually or in pairs. Provide at least one glacier photo set to each student, along with a glacier photo comparison worksheet. This worksheet is a Venn diagram. Explain that students should complete the section at the top, then list the common features of each photo in the middle, and note the differences in each of corresponding sections. Finally, they should note the major changes at the bottom of the page.
Explanation: (30-45 minutes)
When all students have finished analyzing their photos, ask them to share their observations and predict what might happen in the next 50 years if the glacier continues to recede. Make a list of the major changes between the two photos noted by each student or pair of students.
Place the list where it will be visible to the entire class.
Elaboration: (10-15 minutes)
Ask students to look carefully at their data sheets, and read the changes they observed for each of the glaciers. Have them answer the following in their science notebooks:
- What seems to be the most common change to occur in the landscape when a glacier recedes?
- How might these changes have affected the living things in the area?
Evaluation:
Formative assessment: walk around and listen as students describe their observations to each other.
Activity 2B: Melting Ice
Focus Question:
Does melting glacial ice cause a change in sea level?
Which will cause the most change in sea level—sea ice changes or glacial ice changes?
Engagement: (10-30 minutes)
Ask students to find a prediction about sea level rise and to bring it to class, provide 10-15 minutes of Internet research time for them to find one or more predictions, or use one of the predictions below. Make a list of different predictions on the board.
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During the period from 21,000 years ago to 2,000 years ago, the global sea level rose 120 meters.
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Since the last ice age 18,000 years ago, sea level has risen about 130 meters. Most of the rise occurred before 6,000 years ago.
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In the twentieth century, sea level began rising an average of 1.7 millimeters per year.
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If this acceleration remains constant, then the 1990 to 2100 rise would range from 0.28 to 0.34 m
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Climate models based on increasing greenhouse gases and a warmer atmosphere indicate that sea level may rise about 4 millimeters per year beginning in 1990, for a total of 0.44 meters by 2090 (International Panel on Climate Change).
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Tide gauges in the United States show considerable variation because some land areas are rising and some are sinking. For example, over the past 100 years, the rate of sea level rise varies from an increase of about 0.36 inches (9.1 mm) per year along the Louisiana Coast (due to land sinking), to a drop of a few inches per decade in parts of Alaska. The rate of sea level rise increased during the 1993-2003 period compared with the longer-term average (1961-2003), although it is unclear whether the faster rate reflects a short-term variation or an increase in the long-term trend. (Intergovernmental Panel on Climate Change [IPCC]. 2007. IPCC Fourth Assessment Report—Climate Change 2007: The Physical Science Basis Summary for Policymakers.
Discuss the differences in predictions. Virtually all scientists agree that the sea level will rise in most locations in the world as the climate warms. However, there are many different predictions about how fast and how high the sea level rises might be. Some scientists have predicted that the sea level will rise about 4 inches by the year 2100, and others have predicted faster and higher rises in sea level. Scientists use complicated computer models to predict sea level rise, and must work with many variables that are not fully understood. Scientists do know that as water gets warmer, it expands, as demonstrated in Investigation 1C. Melting ice from glaciers and ice sheets will also add water to the ocean.
Ask students if they can think of other factors that scientists would need to know to make an accurate prediction. (Examples: the amount of ice that melts each summer and the amount of re-freezing that occurs each winter, and where ice melt occurs in relation to deep or shallow ocean basins areas or shallow nearshore areas). Does the type of ice matter? Does it make a difference if the melting ice comes from the sea or from the land? In this experiment, you will take a look at how melting land ice (glaciers and ice sheets) changes sea levels.
Exploration: (40-50 minutes)
Ask students to remember what happened to the water level of the cup when the ice cube melted. Review with them that the activity was to simulate the melting of an iceberg or chunk of ice in the ocean. Based on their knowledge, ask them to predict what might happen to the sea level when glaciers or ice sheets melt. Ask students to write their prediction and their thinking in their science notebooks. Hopefully, students will predict correctly. But scientists can’t always assume their predictions are correct; so if possible, they conduct an investigation to test their prediction. Ask students how they might design an activity that simulates a glacier or ice sheet melting. (A couple of ideas are to mold a piece of clay into a mountain shape in the cup, or to place a piece of wood in the cup to represent land.) Discuss student ideas to make sure their ideas will work. Then pass out materials and let them carry out the investigation.
Each pair of students will need:
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Plastic cup or other container that will hold water
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Clay, rocks, or other material that does not float, to represent land in the container
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Ice cube
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Permanent marker or tape
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Water
Students will place the “land” in the container, and then pour water in until it is about half full.
Using a permanent marker or piece of tape, mark the water level on the container.
Place the ice cube on the “land.” When the ice cube has melted, check the water level in the container to see if it has changed. If it changed, mark the new level.
Explanation: (30 minutes)
Allow students to share their predictions and findings. Ask for explanations for why the water level in the cup changed. Ask students to reflect on the following question in their science notebook: What does this experiment suggest might occur to the sea level if glaciers continue to melt?
Extension: (5-35 minutes)
Depending on time, and on students’ levels, you may also wish to discuss the idea of isostatic rebound (See the section on isostatic rebound in Teacher Background). To see the direction and magnitude of trends in sea level change in areas of the Gulf of Alaska, many of which are downward as rebound of the land more than compensates for sea level rise, go to NOAA's Tides and Currents site and click on the Gulf of Alaska.
The Center for Remote Sensing of Ice Sheets has an interactive world map of sea level rise.
Evaluation: (10 minutes)
Ask students to add to the ladder of learning in their science notebooks by adding a rung with information about land ice. Ask them to also reflect on the implications of rising sea levels for people who live in Alaska and other parts of the world.
Extensions:
Have students design and conduct an experiment to measure the reflectivity of land, water, and ice and determine whether increasing the extent of land and water compared to ice and snow-covered ice would increase or decrease the amount of sunlight and heat reflected from the earth as a whole. (See albedo activity extensions in Investigation 1.)
Activity 2C: Stream Table
Focus Question:
How do melting glaciers affect stream flows, erosion, and habitats for fish and wildlife?
Engagement: (20 minutes)
Ask students to think about the glacier photos that they analyzed. What were some of the changes to the landscape they observed after the glacier had receded? In addition to exposing land that was previously covered by ice, the water released can change the landscape and the quality of water in streams. Show them the stream table and explain that you can use it to show the effects of a stream on the land. See Teacher Background for Stream Table instructions.
Exploration and Explanation: (50-60 minutes)
Ask students to closely observe the stream table before you begin, noting how the surface appears.
Modeling Erosion: Build your stream table with sand. Use a watering can to simulate "rainfall" by holding it slightly above the high end of the stream table. Observe the small streams that form in the sand and drain into the original stream you etched out.
Ask students to watch the flow of water as it erodes the sand. What do they notice? How are the different grain sizes affected by the water flow? How is the water flow affected by different size sand or rock particles?
Ask them to sketch the resulting landscape and write an explanation of how a stream can erode the land.
Modeling Head-Cutting and Canyon Formation: Build the stream table with sand, but mound up the sand at the upper end of the tray. Create a channel through the top of the mound. Pour water from the upper end in a steady stream and observe.
Ask students to watch the flow of water as it erodes the sand. What do they notice? What happened to the channel at the edge of the mound?
Ask them to sketch the resulting canyon and write an explanation of how the water can extend the length and depth of the canyon.
Modeling Siltation: Build the stream table with potting soil, or potting soil over a base of sand or gravel. Place the tubing in the lower end of the stream channel and place the funnel below the end to direct the flow into a bucket. Use the watering can to simulate rainfall, continuing to pour until water runs off into the bucket. If you used a pan instead of a cookie sheet, you can mound up the potting soil on either side of the channel and pour water from the watering can down the sides as well as at the upper end until it runs off. Continue to add water until the water collected at the end is cloudy or muddy.
Ask students to watch the flow of water as it falls on the soil. What do they notice? What is the difference in the size of particles that get moved by the water and make it cloudy or muddy?
Ask them to write a description of what happened. Ask them to consider how muddy water might affect the plants or animals that live in the water.
To model the effect of increased flows that would occur with accelerated glacial melt, use the watering can for a set period of time and keep a sample of the runoff, then pour water down the sides of the mounds on either side of the channel or into the upper end of the channel for the same amount of time and take a sample of the runoff. Compare the two samples. Which is more cloudy or muddy? (This is a good lead-in to the Secchi disk activity.)
Have students look for examples of erosion, canyon formation, and siltation in their local watershed. They can look at a map of Alaska to see where the glaciers and ice fields are located in relation to the examples they found. Is it possible that the examples were a result of glacial retreat? If not, what caused the change?
Extension: (30 minutes):
Watch the visualization of a canyon-forming process
Modeling a Delta: Form a large pool of water (a lake or ocean) at the end of the stream table. Watch as sediments are carried and deposited at the edge of the ocean. After one delta has formed, raise the stream table to allow new deltas to form.
Modeling Melting Glacier Effects: Mix 1 liter of sand and gravel with 500 ml clay and water. Freeze the mixture until solid. Place the frozen mixture on the raised portion of the stream table, and observe the results.
Adapted from The University of Nebraska-Omaha stream table activity.
Activity 2D: Transparency/Turbidity
Focus Questions:
How does increased turbidity that results from melting glaciers affect the conditions for life in the streams?
Engagement: (30-40 minutes)
Distribute the Peninsula Online news article, "Small fry may be big problem" to students and ask them to read it to themselves.Then ask, "To what do scientists attribute to the small size of the salmon fry in Skilak Lake?" Ask students to recall what happened in the stream table when the water was poured over the soil. (water became cloudy)
Explain that when glaciers move, the ice scrapes over the ground or bedrock and grinds it up into very fine particles called glacial silt. When the glacier melts, this silt is washed out beneath the glacier and is deposited into the streams and lakes. It is so fine that it does not quickly settle to the bottom and can be suspended in the water, causing the water to appear cloudy or turbid.
Ask students to help develop definitions of transparency and turbidity: Water without any matter suspended in it would be completely clear or transparent, and light would pass right through it. Water has a certain capacity to hold matter in suspension until the density of the matter exceeds the density of the water, at which point the matter sinks. Any matter suspended in water scatters and absorbs light. Turbidity is a measure of the relative amount of light scattered and absorbed by water because of the suspended matter in the water.
Divide students into groups of 2 or 3, and give them the following list of terms:
- Changing Climate
- Glacier
- Hurricane
- Sediment
- Transparency
- Turbidity
- Light
- Phytoplankton
- Zooplankton
- Food Chain
Students should write each term on a sticky note and arrange them into a concept map on a piece of paper. After discussing the relationships of these ecosystem elements and developing their concept map, each student should copy the concept map into their science notebook, along with any questions they have.
Exploration: (50-60 minutes)
Students will make a Secchi disk and use it to measure the transparency of the water, which will indirectly measure turbidity.
The following materials should be available for each group of students:
- Large containers with water (1,000 ml beakers)
- Powdered milk
- Ruler (with centimeters)
- String
- White plastic yogurt, sour cream, or cottage cheese container lid
- Nail or sharp object to make a hole in the lid
- Permanent black marker
- Pencil and data sheet
- Duct tape
- Nuts or washers to use for a weight
- Measuring cups
- Calculator
Divide students into small groups and distribute the Transparency/Turbidity Lab instructions.
Students will learn a method of measuring turbidity indirectly by measuring transparency with a Secchi disk. Using descriptions of a Secchi disk and materials provided, they will make a mini-Secchi disk and take measurements in a beaker.
Adapt the labs according to the abilities of your students, providing fewer or more instructions and example data tables if needed. You may wish to have them graph the data.
Explanation: (25 minutes)
The student lab instructions ask students to Analyze and Conclude. In their science notebooks, they will be completing the following:
- Summarize your findings (the results of your experiments).
- If you were on a boat in the ocean using a Secchi disk, what would your data collection table look like? Are there some variables you would need to control if you were taking measurements over time?
- How do you think turbidity (the cloudiness of the water) might affect:
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The amount of light that will pass into the water column and be available for photosynthesis by marine or aquatic organisms?
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The amount of zooplankton available as food for young salmon and other fish?
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How fast salmon fry and smolt can grow and their size at migration from fresh water to the ocean?
4. Do you think that rapidly-melting glaciers are most likely to increase or reduce water transparency in glacial lakes and streams?
Elaboration: (10-15 minutes)
When all the groups have finished, share and discuss the group responses to the questions as a class, and correct misconceptions.
Evaluation: (10 minutes)
Each student should return to the concept map in their notebook and revise it, adding new terms and connections, and changing it as needed.
Check science notebooks for responses to the lab questions.
Extension:
Have students construct a standard Secchi disk (20 cm diameter for lakes and 40-50 cm for marine waters) and measure the transparency of local water bodies, taking measurements over time. It may be interesting to see how the turbidity changes after a big storm or a hot, dry spell.
Activity 2E: Glacier Game
Focus Question:
How do melting glaciers affect stream flows, erosion, and habitats for fish and wildlife?
Engagement: (5-10 minutes)
Briefly revisit the Glacier Change photos from Activity 2A.
Now that students have seen glaciers retreating, play the Glacier Game to introduce them to a range of effects that melting glaciers can have on land and river ecosystems. Through repetition and game-play the students will (inadvertently!) become familiar with these effects.
Two sizes of the game board are included. Glacier Game Board #1 is designed to be printed on one 11" x 17" piece of paper. Glacier Game Board #2 is designed to be printed on two 8.5" x 11" pieces of paper, then glued or taped together.
Before playing the game, ask students to respond to the following question in their science notebooks, in a format that is easy to follow and can be shared with others.
What are some of the physical and biological effects of increased glacier melting along the course of the river?
Exploration and Explanation (20-30 minutes):
Introduce the game by telling students, “You and your team-mates have just been transformed into snowflakes that fell at the head of Seagrant Glacier a long time ago. Over time more and more snowflakes fell on top of you, and you have been compressed into an ice crystal. You slowly start to move down the slope. Roll dice (or a random number cube) to find out what happens to you on your journey to the ocean! Who will make it to the ocean first?”
Allow student teams to play long enough to have visited most of the spaces on the board. Some teams may play more than once.
Elaboration: (30-45 minutes)
Once students understand some of the potential impacts of melting glacier ice, have them consider the possible effects and impacts on ocean ecosystems from melting sea ice.
Brainstorm a list of possible impacts.
(Examples: loss of habitat for polar bears and seals who use ice as a habitat, less sunlight and heat reflected back to the atmosphere, change in timing of spring phytoplankton bloom, animals that use the edges of sea ice are moving northward, new channels for shipping and tourism)
Ask each student to make five “consequence” cards for a Sea Ice game.
Put these together into a class set as follows:
Ask for a volunteer to read one of his/her consequence cards. Ask the class, “Who has the same or a similar consequence?” Discuss the consequence and if it is correct and appropriate, record it on the board or an overhead projector.
Ask for a new consequence, and repeat until all the class impact cards have been included.
Extension:
Students may want to develop a new game board for Sea Ice impacts, and share it with others.
Evaluation: (5-15 minutes)
1. Play “No Hands Questioning.” After wait time, call on students to provide an effect of increased glacier melting on the landscape and/or ecosystem. Students know that everyone needs to be ready to share ideas. Make a “class list” as you go, so students’ ideas will be reinforced or added to.
2. Use an exit ticket strategy, “Point of Most Significance.”
Students write down the most important points learned from the game on an exit ticket to turn in when they leave.
Teacher Preparation
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Tips from Teachers |
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No tips are currently available. |
Read through the entire investigation, the supplemental materials, and the teacher background. Gather materials for the activities.
Print and copy student handouts. Print and assemble game boards and gather dice and markers for the game. Prepare to show any online resources.
For Activity 2A, load the Glacier Photos onto student computers or copy the Alaska Glacier Photos, and copy the Glacier Photo Comparison Worksheet.
For Activity 2B, gather and prepare materials for the Melting Ice activity.
For Activity 2C, set up and practice using the Stream Table.
For Activity 2D, gather materials for constructing mini Secchi disks. Copy lab handout.
For Activity 2E, copy cut and glue game board. Gather game markers and dice.
Curricular Connections
Math: Graphing and statistics
Literacy: Science Notebooks
Social Studies: Mapping, Ice Age
Technology: Excel graphing, Internet searching
Alaska Science Standards and Grade Level Expectations Addressed:
6th Grade:
The student demonstrates an understanding of the processes of science by
SA1.1 asking questions, predicting, observing, describing, measuring, classifying, making generalizations, inferring, and communicating.*
SA1.2 collaborating to design and conduct simple repeatable investigations. (L)
The student demonstrates an understanding that interactions with the environment provide an opportunity for understanding scientific concepts by
SA3.1 gathering data to build a knowledge base that contributes to the development of questions about the local environment (e.g., moose browsing, trail usage, river erosion). (L)*
The student demonstrates understanding of the structure and properties of matter by
SB1.1 using models to represent matter as it changes from one state to another.
The student demonstrates an understanding of the interactions between matter and energy and the effects of these interactions on systems by
SB3.1 recognizing that most substances can exist as a solid, liquid, or gas depending on temperature.
The student demonstrates an understanding of how science explains changes in life forms over time, including genetics, heredity, the process of natural selection, and biological evolution by
SC1.2 recognizing that species survive by adapting to changes in their environment.
The student demonstrates an understanding that all organisms are linked to each other and their physical environments through the transfer and transformation of matter and energy by
SC3.2 organizing a food web using familiar plants and animals.
The student demonstrates an understanding of the forces that shape Earth by
SD2.3 describing how the surface can change rapidly as a result of geological activities (i.e., earthquakes, tsunamis, volcanoes, floods, landslides, avalanches).
The student demonstrates an understanding that solving problems involves different ways of thinking by
SE2.1 identifying and designing a solution to a problem.
SE2.2 comparing the student’s work to the work of peers in order to identify multiple paths that can be used to investigate a question or problem. (L)*
7th Grade:
The student demonstrates an understanding of the processes of science by
SA1.1 asking questions, predicting, observing, describing, measuring, classifying, making generalizations, inferring, and communicating.*
SA1.2 collaborating to design and conduct simple repeatable investigations, in order to record, analyze (i.e., range, mean, median, mode), interpret data, and present findings. (L)
The student demonstrates an understanding that interactions with the environment provide an opportunity for understanding scientific concepts by
SA3.1 designing and conducting a simple investigation about the local environment. (L)
The student demonstrates understanding of the structure and properties of matter by
SB1.1 using physical properties (i.e., density, boiling point, freezing point, conductivity) to differentiate among and/or separate materials (i.e., elements, compounds, and mixtures).
The student demonstrates an understanding that solving problems involves different ways of thinking by
SE2.2 comparing the student’s work to the work of peers in order to identify multiple paths that can be used to investigate a question or problem. (L)
8th Grade:
The student demonstrates an understanding of the processes of science by:
SA1.1 asking questions, predicting, observing, describing, measuring, classifying, making generalizations, inferring and communicating.*
SA1.2 collaborating to design and conduct repeatable investigations, in order to record, analyze (i.e., range, mean, median, mode), interpret data, and present findings.* (L)
The student demonstrates an understanding of the attitudes and approaches to scientific inquiry by
SA2.1 recognizing and analyzing differing scientific explanations and models.
The student demonstrates an understanding of the forces that shape Earth by:
SD2.1 interpreting topographical maps to identify features (i.e., rivers, lakes, mountains, valleys, islands, and tundra).
The student demonstrates an understanding that solving problems involves different ways of thinking by
SE2.2 comparing the student’s work to the work of peers in order to identify multiple paths that can be used to investigate and evaluate potential solutions to a question or problem. (L)
The student demonstrates an understanding of how scientific discoveries and technological innovations affect our lives and society by:
SE3.1 predicting the possible effects of a recent scientific discovery, invention, or scientific breakthrough. (L)
Essential Questions:
Enduring Understandings:
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