Snow and Ice, Part 2: How Does Ice Change?

Transcription

1 Snow and Ice, Part 2: How Does Ice Change? We have been observing how things, like snow, can change by melting. We have used thermometers to compare the warmer temperature of the room to the colder temperature of the snow as we watched the snow change from a solid to a liquid. Now you will use what you learned from your snow investigation to observe another solid ice. Your investigation task is to make observations and collect data while investigating melting ice cubes. Use your recording sheet to do 3 things: Draw what your cup of ice looks like when you begin. Count the ice cubes you put into the cup. Make a prediction about how much water there will be when the ice cubes melt. Make a prediction about how long it will take for the ice to change to water. Draw and write to show what happened. 1 of 11

2 Suggested Grade Span K 2 Task We have been observing how things, like snow, can change by melting. We have used thermometers to compare the warmer temperature of the room to the colder temperature of the snow as we watched the snow change from a solid to a liquid. Now you will use what you learned from your snow investigation to observe another solid ice. Your investigation task is to make observations and collect data while investigating melting ice cubes. Use your recording sheet to do 3 things: Draw what your cup of ice looks like when you begin. Count the ice cubes you put into the cup. Make a prediction about how much water there will be when the ice cubes melt. Make a prediction about how long it will take for the ice to change to water. Draw and write to show what happened. Big Ideas and Unifying Concepts Cause and effect Change and constancy Physical Science Concepts Properties of matter Transfer and transformation of energy Mathematics Concepts Comparison of attributes or effects Data collection, organization and analysis Measurement Time Required for the Task Approximately 2 to 3 hours in the classroom or at home. 2 of 11

3 Context This task was a homework extension for my first and second graders to do with their families. First, I took advantage of a spontaneous scientific moment, which involved collecting snow into cups from the first snowstorm. (See "Snow and Ice, Part 1: How Does Snow Change? ) In the guided investigation with snow, the class observed and recorded data for one minute, using thermometers to check the temperature of the room and the temperature of the snow. The guided snow investigation led to this homework task; however, this investigation could also be done in the classroom to extend and develop better understanding of states of and changes in matter. For this, the children followed a similar process, making observations and collecting data using a recording sheet, while melting ice cube at home. What the Task Accomplishes This investigation enabled the students to make extensions by comparing their prior observations and investigation with snow to their ice task. This provided more opportunity to observe changes in matter and to practice measurement skills. The snow and ice tasks included using observation skills with the senses of sight and touch, analyzing prior knowledge, predicting, recording data and communicating results with their peers in the classroom. This task also was used as an introduction and connection to components of the water cycle, which was discovered by many children through observation and discussion. How the Student Will Investigate Each child took home the same size plastic cup that was used with the snow investigation and was asked to fill it with ice cubes from home. Students predicted how much water would be left and how much time it would take for the ice cubes to melt. The first and second graders were also encouraged to notice any similarities or differences between the melting snow and the melting ice. The children were asked to make a written conclusion on their recording sheet, based on their prior experiences and observations at home. The recording sheets were sent home in Monday homework folders and due back by Thursday to share in a classroom discussion. Parents were encouraged to work with their children to assist with recording, when needed. Interdisciplinary Links and Extensions Science/Mathematics Compare and measure the water resulting from melted snow, crushed ice and ice cubes. Integrate components of the water cycle (condensation and evaporation) with the water that is left in the plastic cups. The class could work in partners to have an ice keeper contest by using a variety of materials to keep the ice cube from melting, connecting problem solving and time. Students could add salt to an ice cube to see the effect of heat transfer from the salt to the ice. 3 of 11

4 Social Studies Collect a variety of fabrics or use catalogs to compare why different materials would be best to wear in cold or hot weather. (Include fabrics such as wool, polyester, cotton, felt, silk, flannel, suede and fleece.) Research and discuss why different cultures wear certain clothing depending on the weather and climate patterns in their environment. Have cooperative groups select a climate and design clothing to match the living conditions. (This could also be done as a pre/post activity for a social studies assessment.) Literacy Rain, Snow, and Ice (Weather Report), by Ann Merk, provides scientific information for this unit of study concerning changes in states of matter. Stopping by Woods on a Snowy Evening, written by Robert Frost and illustrated by Susan Jeffers, and other seasonal poetry provide beautiful sources to model writing poetry with seasonal changes. The children could design character puppets to tell their own story about how their character might change through the seasons, using clothing, recreation, hunting/gathering as a theme. Art Have the class design a mural to demonstrate changes from winter to spring for people, plants and wildlife. Design a sequential series of pictures to illustrate a melting snowball, snowman or ice cube, and decide where the water will go or how it will be recycled. After going on an outdoor walk in the neighborhood, illustrate where the snow gathers on trees, fences, bushes and houses using a collage of paint, cotton balls and chalk. Mathematics Use Graph Club[reg] as a technology tool to graph data about weather patterns from a month of classroom observations and data, the rainfall in different ecosystems and/or cycles of the moon. Teaching Tips and Guiding Questions I suggest using four cubes or more, depending on the size of the cubes. Otherwise it will be difficult for students to see much water after the cubes melt. Here are some suggested questions to ask while students investigate: Why is the amount (volume) of ice greater than the liquid water? Do they weigh the same even if they do not look the same? How could we find out? Which is more dense snow or ice? Would the same amount of snow and ice melt to give us the same amounts of water? How could we find out? How do we keep our bodies warm when we are outside in the cold? Why do we wear certain fabrics for outer clothing in the winter? How do mammals, reptiles, amphibians and insects adjust to colder (winter or nighttime) temperatures? How could you keep your ice cube from melting? How does this relate to using a cooler, a thermos or an ice chest to keep food hot or cold? 4 of 11

5 How is oobleck more like a solid or liquid? How would you categorize it? How does temperature affect the rate of changes for ice, snow crystals or a chemical reaction like bath cubes? How does one fabric or object absorb water more than another? How could you determine if ice pops are softer than ice? Why is salt spread on icy roads? Where does the heat come from to melt ice on roads? Why is salt added to ice cream? Concepts to be Assessed (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 properties of materials and make predictions and classify materials by their similarities and differences. Students observe and compare physical properties of matter. Students observe that ice is a form of matter (it results from water changing its state to become solid/frozen when a transfer of heat has occurred). Physical Science Transfer and Transformation of Energy: Students understand that energy is a property of many substances and is transferred in many ways and that an increase or decrease of heat can change the ice/snow to another state (water or water vapor). Scientific Method: Students observe and explain cause-effect relationships, with some justification, using data and prior knowledge. (Watching for a physical change in a solid ice or snow to a liquid, for example.) Students determine the patterns and/or which kinds of change are happening by collecting data (observing and measuring temperature) about melting ice or snow (change and constancy). Mathematics: Students understand and use precise measurements in describing events, answering questions and providing evidence for scientific explanations. Students compare attributes or effects and collect, organize and analyze data appropriately. Skills to be Developed (Science process skills to be assessed using the Science Exemplars Rubric under the criteria: Scientific Procedures and Reasoning Strategies, and Scientific Communication Using Data) Scientific Method: Observing, predicting, hypothesizing, collecting/recording data, controlling variables, manipulating tools, drawing conclusions, communicating findings and raising new questions. Other Science Standards and Concepts Addressed Scientific Theory: Students look for evidence that explains why things happen and modify explanations when new observations are made. 5 of 11

6 Scientific Method: Students describe, predict, investigate and explain phenomena. Physical Science Properties of Matter: Students describe and sort objects and materials according to observations of similarities and differences of physical properties. Physical Science Transfer and Transformation of Energy: Students understand that energy is a property of many substances and is associated with heat, light, electricity, mechanical motion, sound, nuclei and the nature of a chemical. Students observe that heat is a form of energy and can cause changes in states of matter. Communication: Students use verbal and nonverbal skills to express themselves effectively. Students interpret and communicate and use mathematical, scientific and technological notation and representation. Mathematics: Students use reasoning strategies, knowledge and common sense to solve complex problems related to all fields of knowledge. Suggested Materials For this investigation, each child needs a clear plastic 5- or 6- oz. cup to take home and a recording sheet. Ice cubes are provided at home to fill the cup. For my class, the materials went home on Monday and were due by Thursday. There were three parts of the recording sheet to be completed. Part 1 reflected what the cup looked like with the ice cubes in it. (I suggested using at least four cubes, depending on the size.) Part 2 involved predicting how much water would be left from the melting cubes, and how long it might take for the cubes to melt. Part 3 asked for a measurement of the water and for scientific conclusions. Possible Solutions When snow or ice melts, air trapped inside is released. The volume of liquid water becomes much less than the volume of snow or ice. Fresh snow has more trapped air than packed snow that has had time to squeeze together. The results of this task will vary depending on the size and the quantity of the ice cubes used. Teachers should look for scientific accuracy, use of any science vocabulary, and understandings from prior knowledge and/or the snow investigation. Students should draw and count their ice cubes in part 1. In part 2, they should make a prediction by shading the amount of water they expect to see (showing less than the volume for the ice cubes indicates use of prior knowledge) and predict how long it will take (more than a few minutes will indicate use of prior knowledge). In part 3, conclusions and observations are made that the solid ice cubes change to the liquid water. A drawing should be included. 6 of 11

7 Task-Specific Assessment Notes Novice This student does not provide a drawing of the setup and does not record the number of ice cubes used. The student does record predictions about how much water might be in the cup when the ice cubes melt and estimates a reasonable time. There is some evidence of conceptual understanding with a conclusion of less water than ice cubes left in the cup, but there is not enough in the explanations to demonstrate scientific reasoning. The student does not note that there was less water left than was predicted, for example. Apprentice This student provides a drawing of the setup but does not record the number of ice cubes used or make any other initial observations. The child does record predictions about how much water might be in the cup when the ice cubes melt. There is some evidence of how the student followed the melting of the ice cubes. It appears that the student timed the activity instead of making a prediction about how long it would take. There is some evidence of conceptual understanding in the student s conclusion, but it needs more explanation to be clear. The meaning seems to translate to: I think the ice is different because the water is liquid. The student uses the science vocabulary of liquid appropriately. The student has not yet linked the reasoning to the prediction or to changes of states of matter. Practitioner This student does provide a drawing of the setup and records the number of ice cubes used and another initial observation. The child does record predictions about how much water might be in the cup when the ice cubes melt and estimates a reasonable time. The final conclusion compares the prediction of one hour in time with the recording of how long it actually did take for the ice cubes to melt. A second comparison is made about the predicted and actual amount of liquid evidence of use of scientific reasoning. There is evidence of conceptual understanding through drawings, observations and appropriate use of science vocabulary ("liquid"). Expert This student s solution is very complete and detailed, with explanations of the scientific observations and procedures and understanding of concepts. This student provided a drawing of the setup and made a recording about the spaces between the smaller ice cubes, the size and number of cubes, and the cup being full at the beginning of the investigation. The student recorded predictions about how much water might be in the cup when the ice cubes melt and made a reasonable time prediction of hours. Recordings also show that the student chose to wait overnight to check the results. There is strong evidence of extended scientific thinking with the connection to the evaporation cycle, and a connection made back to the earlier snow investigation from the classroom. There is evidence of conceptual understanding through drawings, observations and appropriate use of science vocabulary ("melted," "evaporation," "droplets"). 7 of 11

8 Novice 8 of 11

9 Apprentice 9 of 11

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11 Expert 11 of 11