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1. The students will construct a data table (outline provided)
   
2. The students will write a journal entry (sample BCR response based on lab results)

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Real World Setting: Education

You are a college student in your school's chemistry lab. You are faced with analyzing a sample. You must determine if it is ionic or covalent, without tasting it. Once you have completed your laboratory analysis, you will explain to your professor the steps you have taken in order to test and classify the sample.

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Level I: Acquiring Data - Data students will acquire in this standards-based task:

Images: Visual observation/summary of behavior of various substances in a laboratory setting.

Skills: Analyzing; Comparing/Contrasting; Testing (following verbal instructions)

Concepts: How to physically observe the state of matter and crystalline structure (or lack thereof) of a common substance; to measure the ability of a common substance to: dissolve, conduct electricity, and melt.

Level II: Visualizing Information - Data from Level I that are visualized as information in this standards-based task: Physical state of matter and geometric structure; physical properties (solubility, electrical conductivity, relative melting point).

Organizing: Students will organize data using the data table provided.

Storing: Students will "store" in advance a comparison/contrast summary of the macroscopic properties of ionic vs. covalent substances using a Venn Diagram or table.

Level III: Applying Knowledge - Visualized information from Level II that is applied knowledge in this standards-based task:

Solving problems: Students will utilize their collective data to complete a sample BCR to level 4 proficiency (topic: the steps to follow in determining whether an unknown substance is ionic or covalent).

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1. Extra processing and response time
   
2. Written copies of orally presented instructional or assessment materials
   
3. Written or photocopied notes of orally presented instruction or
   assessment materials
   

Use of Resources - The school will provide laboratory equipment and laboratory setting (reserved in advance) and classroom time to complete the task

Use of Resources - The students will provide classroom materials such as pencils, paper, notebooks and homework time

Customer for Student Work - The students will present their work as evidence of task completion to peers and the teacher.

Assessment of Student Work - The following people will be involved in assessing student work generated to complete the task: the student's teacher.

Reporting Results - The assessment results will be reported as a score point on the Rubric for Ionic and Covalent Mini-Lab and as a letter grade (converted from score points earned on rubric divided by the maximum possible points)

Timeline - The estimated time needed to plan, teach, and score this task is two planning periods and one class meeting.

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Five Es Model of Instruction

Activity 1. Engagement: The activities in this section capture the students' attention, stimulate their thinking, and help them access prior knowledge.

December 6th 2005
10 minutes

1. Define: difference between ionic and covalent (molecular) bonding (in terms of electron behavior)
2. Review Notes on Ionic vs. Covalent (from previous lesson: table or Venn diagram summary)

5 minutes
Discuss: Lab Procedure and Safety Protocols

Activity 2. Exploration:
1. Investigation (30 minutes)
- design and/or perform

Go to Lab
In lab groups - perform tests and record data for the 8 substances provided (salt NaCl, sugar C12H22O11, vegetable oil, wax, cobalt II chloride CoCl2, starch, copper sulfate pentahydrate CuSO4 * 5H2O, and lithium chloride LiCl).

Teacher demo: melting behavior of each substance, using bunsen burner or propane torch.
Point out: production of gas / steam from various substances, color changes, and behavior of hydrates.

Technology: magnifying glasses, microconductivity testers
Materials: beakers w/ water, stirrers, bunsen burner or propane torch (teacher demo only; samples of: salt NaCl, sugar C12H22O11, vegetable oil, wax, cobalt II chloride CoCl2, starch, copper sulfate pentahydrate CuSO4 * 5H2O, and lithium chloride LiCl
Student product or performance: completed data table (Section III of abbreviated lab report outline)

Activity 3. Explanation: Students are now involved in an analysis of their exploration. Their understanding is clarified and modified because of reflective activities.
10 minutes

1. Student analysis and explanation - Answer IV. Analysis question (A) in complete sentences: based upon the data, classify each substance on the data table as either ionic or covalent
   
2. Supporting ideas with evidence - see data table
   
3. Structured questioning Ask: how do you know / what makes you think that (substance) is ionic (or covalent)?
   
4. Teacher explanation: point out that sugar may at first appear ionic (solid, crystalline, dissolves), but is actually a covalently-bonded substance.
   
5. Thinking skills activities:
   • comparing, classifying: each substance based upon the data
   • abstraction: students should be able to infer the submicroscopic (atomic) behavior of the atoms and their bonding within each substance based upon their macroscopic observations; for example, salt NaCl is solid, crystalline, dissolves, conducts electricity when dissolved, and has a high melting point (will not melt even with gas flame).
   • error analysis: several of the ionic substances may not have demonstrated electrical conductivity, most likely due to insufficient concentration and/or lack of a strong current from the power source (ie, an old battery). If possible, using a state-of-the-art microconductivity tester with a resistor in the circuit, prove to students that ALL of the ionic substances really do conduct an electric current when dissolved (even though some may conduct better than others; ie, for some the light bulb may light; for others it may only flicker, or not respond at all, but a current can still be measured).
     

Technology: sophisticated microconductivity tester
Materials: samples of: salt NaCl, cobalt II chloride CoCl2, copper sulfate pentahydrate CuSO4 * 5H2O, and lithium chloride LiCl
Student product or performance: Correct and complete response to IV. Analysis question (A).

Activity 4. Extension: This section gives students the opportunity to expand and solidify their understanding of the concept and/or apply it to a real world situation.

15 minutes

1. Problem solving: Read aloud (or ask a student volunteer to read out loud) the IV. Analysis question (B), which is also a sample BCR. Have a student explain the importance of the question and what it is really asking.
   
   
2. Decision-making: refer students to their completed data table. Guide them (using student volunteers) into a coherent verbal explanation of how to complete all 5 tests in order to determine whether the unknown substance is ionic or covalent. Once they have decided how to articulate the process, emphasize that they must write down their answers. Answers do not to be identical; encourage students to develop responses in their own words that accurately explain what must be done. Emphasize to students that in order for their response to meet the level 4 rubric requirement for a science BCR, they must specifically explain that if the substance does not meet all 5 of the criteria, it most likely is NOT ionic.
   

Technology: overhead projector/screen if desired (or use chalkboard or whiteboard)
Student product or performance: Level 4 BCR response

Activity 5. Evaluation: Evaluation occurs throughout the lesson. Scoring tools developed by teachers and students target what students must know and do. Consistent use of scoring tools improves learning.

Rubric: (explained at beginning of lesson)

Error analysis: if time, present 1 or more examples of sample BCR responses for the IV. Analysis (B) question written the way a student would explain it. Each sample should contain one or more errors that prevent the response from meeting the level 4 BCR rating. Have students identify what is wrong with each analysis.

Technology: overhead projector/screen (if desired)
Materials: handouts of sample BCR responses
Student product or performance: level 4 BCR responses; also ability to analyze other's errors and improve their own analytical skills and responses in order to minimize such errors

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Rubric for Ionic and Covalent Mini-Lab:

MiniLab: 120 pts

1. Definitions (15 pts)
   
2. Notes (25 pts)
   
3. Data and Observations (30)
   
4. Analysis (50 pts: 15 1st part-results summary; 35 pts 2nd part - critical thinking (scaled from the Science Rubric where 0 to 4 is replaced by 0 to 35)
   

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Data Analysis:

1. Number of students who completed and turned in the MiniLab for grading: 72
   
   
2. Number of these students who scored 70% or above (84 points or more out of total possible 120 pts): 55
   
   
3. Percentage % of these students who scored 70% or above (84 points or more out of total possible 120 pts): 55/72 = 76%
   
   
4. Trends in student performance:
   • Of students who scored at or above 70% on this activity, 87% (47 students) completed all sections of the Minilab according to the instructions. Of students who did not complete all sections, the major error was missing/incomplete data due to one or two boxes on data table being left blank. The second-highest error was a failure to completely answer an Analysis question.
     
   • Of students who did not score at least a 70% on the minilab, the major errors, in order from highest to lowest occurrence, were: Incomplete data table (part III), Incomplete Analysis (part IV), and Missing definition (part I).
     
     
5. Contributing factors: One or more of the following may have contributed to less than average (70%) scores earned by 24% of students who completed the activity.
   • Failure to read and follow all directions
     
   • Did not use complete sentences
     
   • Did not hear/understand the warning that failure to complete all boxes of data table would result in loss of points
     
   • Did not look over assignment (check for completion) before handing in to be graded
     
     
6. Implications for student performance: Students who do not complete all parts of assignment according to instructions have about a 1 in 4 chance of scoring below the minimum passing grade.
   

Reflection: My students' overall performance level may be positively impacted if I: assign, or require students to assign, one "Reader" for each lab group who is responsible to read all directions to the group as they work. Also, students may benefit from having one or two "Checkers (Proofreaders) from each lab group who spot-check their group members' papers and their own everyone's paper for completeness before the assignment is handed in.

Other ways in which this and similar lessons might be improved: As part of students' pre-laboratory training and preparation early in the semester, show samples of work that contain various errors, such as: incomplete data, failure to answer using complete sentences, failure to follow directions, and fallacious logic, and teach them how to identify common errors that they should strive to avoid. This practice can be continued at intervals throughout the semester in order to help students to develop a more "critical eye" in analyzing their own and other's work.

It may also be helpful to informally survey students who did not perform well to find out why they make the mistakes that they did, or why they did not complete the assignment, and what I might do to help them to improve.