TITLE: Chembalancer
TASK DEVELOPER: V. Anderson
GRADE AND CONTENT AREA: Chemistry
SCHOOL: Mergenthaler Vocational Technical Senior High School
STANDARDS:

Maryland Core Learning Goals, Expectations, and Indicators
Science: Grades 9-12

Goal 4 Concepts Of Chemistry: The student will demonstrate the ability to use scientific skills and processes (Core Learning Goal 1) to explain composition and interactions of matter in the world in which we live. (NT, NTB = Not Tested)

Expectation 4.4: The student will explain and demonstrate that matter undergoes transformations in such a way that the products have properties that are very different from those of the starting materials.

Indicator 4.4.3: The student will use the law of conservation of mass and energy to balance simple equations. AT LEAST: use appropriate coefficients to balance a given symbolic equation.

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PERFORMANCES:

The students will write a short essay explaining a balanced equation.

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SMARTSKILLS:

Level I: Acquiring Data - Data students will acquire in this standards-based task: Take data from equation to create a balanced equation by adding coefficients.

Level II: Visualizing Information - Data from Level I that are visualized as information in this standards-based task: Counting individual atoms and elements

Level III: Applying Knowledge - Visualized information from Level II that is applied knowledge in this standards-based task: Organizing data regarding reactants and products in a "t-type" chart

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PREFERENCES:

Task Approach - The students will complete the task individually using the Internet.

Task Delivery - The task will be organized and delivered through a password-protected elearning program on the Internet.

Assistive Technology Accommodations - Students with special needs will require the following presentation of information: Extra processing and response time.

Use of Resources - The school will provide computer hardware and software.

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

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

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

Reporting Results - The assessment results will be reported as a score point on a rubric.
INSTRUCTIONAL ACTIVITIES:

Five Es Model of Instruction

Activity 1. Engagement:
(10 minutes)

Drill: Identify the number of atoms of each element present:

  1. CO2
  2. H2SO4
  3. C6H6

Go over--have students show on board: review how to read the formula

Activity 2. Exploration:
(10 minutes)

Identify how many atoms of each listed element are present in the equation.

Na2O2 + H2SO4 --> Na2SO4 + H2O2
TOTAL:
Na?
H?
O?

Activity 3. Explanation:
(10 minutes)

Notes on components of an equation balancing

Activity 4. Extension:

Use the Chembalancer website:

http://www.dun.org/sulan/software/trial/chem1/chemBalancer/worksheet.htm

and have students practice balancing equations online. They will complete a worksheet that goes with the website to show their work.

Technology: computer lab
Materials: worksheet
Student product or performance: completed worksheet
Scoring: accuracy grade

Activity 5. Evaluation:
Evaluation occurs throughout the lesson.

Examine the equation: H2 + 2 O2 --> H2O.

Is it balanced? If not, explain what the error is, which element(s) is out of balance, the process you would follow to properly balance the equation, and then state the proper balanced equation.

(see scoring rubric for science)

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SCORING:

HSA RUBRIC FOR CONSTRUCTED-RESPONSE ITEMS: SCIENCE

LEVEL 4
There is evidence in this response that the student has a full and complete understanding of the question or problem.

  • Pertinent and complete supporting details demonstrate an integration of ideas.
  • The use of accurate scientific terminology enhances the response.
  • An effective application of the concept to a practical problem or real-world situation reveals an insight into scientific principles.*
  • The response reflects a complete synthesis of information.

LEVEL 3
There is evidence in this response that the student has a good understanding of the question or problem.

  • The supporting details are generally complete.
  • The use of accurate scientific terminology strengthens the response.
  • The concept has been applied to a practical problem or real-world situation.*
  • The response reflects some synthesis of information.

LEVEL 2
There is evidence in this response that the student has a basic understanding of the question or problem.

  • The supporting details are adequate.
  • The use of accurate scientific terminology may be present in the response.
  • The application of the concept to a practical problem or real-world situation is inadequate.*
  • The response provides little or no synthesis of information.

LEVEL 1
There is evidence in this response that the student has some understanding of the question or problem.

  • The supporting details are only minimally effective.
  • The use of accurate scientific terminology is not present in the response.
  • The application, if attempted, is irrelevant.*
  • The response addresses the question.

LEVEL 0
There is evidence that the student has no understanding of the question or problem.

  • The response is completely incorrect or irrelevant or there is no response.

* On the High School Assessment, the application of a concept to a practical problem or real-world situation will be scored when it is required in the response and requested in the item stem.

Updated 2002

Source: http://www.mdk12.org/instruction/curriculum/science/assessments.html

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RESULTS:

Organize: The following data resulted from scoring student work with my rubric:

Number of students who performed below the proficient level on my scoring tool;

For the Chem balancer activity:
Period 1: 5 students were below proficient
Period 2: 4 students were below proficient

For the BCR that acccompanied the activiy:

Period 1: 14 students were below proficient (scoring 1 or 2)
Period 2: 15 Students were below proficient (scoring 1 or 2)

Analyze: I will examined the data to look for trends, contributing factors, and implications of student performance over a series of assessments of the same learning standard.

Based on this data, it would appear that the problem may not lie in the skill of balancing the equations, but in the ability/willingness to write the Brief Constructed Response (BCR)..

One skill problem I noticed in common among the BCR responses was the fact that students failed to put the coeffiecents in their simplest terms.

Reflect: I noticed that many of my students seemed to grasp the mechanical aspects of balancing chemical equations but were unable, or unwilling, to write it out in a BCR.

As I look at my practice, I see that it may be nessisary to give my students a template to follow when writing a BCR. My concern is that this will become a crutch for the students, not a stepping stone. I have observed that many of my students expect that anything that they may have once used to help them (tool, guide, outline, etc.) should be availabe at all times. They do not appear to want to grow beyond that point of assistance.