A Vegetable a Day Will Light Your Way

A VEGETABLE A DAY WILL LIGHT YOUR WAY

CARLA ORTEGO AND KAYE THIBODAUX

Louisiana Curriculum Framework Content Strand / Physical Science
Science as Inquiry / Grade Level / 5-8
Objective:The students will;

1. Design and conduct a scientific experiment using Algebra and Physical Science to gather, analyze, and interpret data.
2. Develop descriptions, explanations, and graphs using data
3. Analyzing tables and graphs to identify relationships exhibited by the data and

making generalizations based upon these relationships.

Teacher Information

Benchmarks (see Reference 1)
SI-M-A1, SI-M-A2, SI-M-A3, SI-M-A4, SI-M-A5, SI-M-A8, PS-M-A9, PS-M-C2, PS-M-C6, A-4-M / Time Frame
One 50-minute class period
Curriculum Integration
Safety, laboratory procedures, laboratory reports, scientific method, electrical currents with voltage readings
Cross Curriculum Integration:
Math - algebra (Linear graph)
Language - lab reports, reflective journals, and social skills. / Materials
Five different types of ” batteries” (potato, pickle, cucumber, onion, and tomato)
TI-83 Plus calculator
CBL
Data Link Cable (“alligator clips”)
CBL voltage probe
5- Zinc rods
5- Copper rods
5- Plastic cups
6- Voltage link cables
Applications
Chemistry, electrician, chemical plant operator, agricultural, graphical analysis / Student Groupings
Cooperative groups
Possible Obstacles to Student Learning
Prior background on pH, acids and bases, understanding of conductivity, use of the technology, experimental design, statistical analysis and graphing.
Opportunities for Assessment

1. Group results with individual lab reports.
2. Reflective journals
3. Graphing analysis
4. Discussion

Lesson Procedure
Exploration: Students will be given a set of materials that are natural resources and investigate the relationship between those items and the ability to become a battery. The amount of electricity that you can gather from these materials, individually and combined, will be a key factor in determining the amount of electrical currents that can be generated to light a light bulb
Materials: Vegetables, voltage probe, CBL, zinc, copper, link cables, TI-83 Plus calculator,
Concept Development: Discussion on usage of CBL and voltage probe, discussion on electrical currents

• Students will list and graph each vegetable in accordance with individual and combined results
• Which vegetable conducts the most voltage? Potato, tomato, etc.

Integration of Technology: At this point, students would test the substances from Exploration with the CBL, graphing calculator, and voltage probe. See laboratory procedure in student handout.
Concept Application: Students will discuss in their cooperative pairs whether the following substances are good conductors of electricity: cucumbers, pickles, onions, tomatoes, and potatoes.
Attachments
1. Student Handout
2.Assessment Rubrics
3. Sample Data
4. References

Student Handout

A VEGETABLE A DAY WILL LIGHT YOUR WAY!!

Set Up

1. Wash each vegetable with tap water, place each one in a plastic cup and line them up in a row, side by side.

1. Measure and cut 6 zinc and 6 copper rods, approximately 3 inches higher than the vegetable being tested.

1. Place zinc and a copper rod into each vegetable. (Make sure you have at least 1” of each rod sticking out of the vegetable.)

1. You will need 6 link cables. Place them on the table.

1. To set up CBL and TI-83 Plus calculator:

a)Hook up the voltage probe to the CBL, placing it into CH 1 and turn on the CBL. Press the MODE on the CBL. Connect the CBL and the TI-83 Plus with a data link cable, and then turn on calculator.

b)Press APPS on the calculator and then select option 2:CHEMBIO from the

APPLICATIONS menu.

c)Press ENTER

d)Enter 1 to SET UP PROBES, then enter 1 for thenumber of probes.

e)Press 5: VOLTAGE

f)Enter Channel number 1.

g)Enter 2: COLLECT DATA

h)Enter 3: TRIGGER PROMPT

YOU ARE NOW READY TO BEGIN THE ACTIVITY!!

Activity

1. Place the cucumber on the table. Place two of the link cables on the cucumber, one on the copper rod and the other on the zinc rod. Connect the red voltage cable to the link on the copper rod, and the black voltage cable to the link to the zinc rod.

1. When the voltage reading on the screen of the CBL stabilizes, press TRIGGER on the CBL. When prompted for a value, enter 1 for the number value of the cucumber. Press ENTER. You should record your data from the CBL by hand into a data table although the calculator will store it in a list for you.

1. Place the potato on the table next to the cucumber. Remove the link cable on the copper rod of the cucumber and place it on the copper rod of the potato. Take another link cable and place it on the copper rod of the cucumber and connect it to the zinc rod of the potato. Choose 1:MORE DATA on the calculator.

1. When the voltage reading on the CBL is stable, press TRIGGER on the CBL. When prompted for a value, enter 2 for the number value of the potato.

1. Repeat steps 3 and 4 for the following vegetables: enter number value 3 for the Onion, 4 for the Tomato, and 5 for the Pickle. Remember that when you are prompted to “enter value”; you are entering the number value for each of the vegetables.

1. When you are finished collecting data, select 2: STOP AND GRAPH.

1. View the graph on the TI-83 Plus graphing calculator. Press TRACE to view the points on the graph. Use the left and right arrow key to move the cursor on the graph. Using these points draw your own graph on the worksheet.

(If a graph does not appear, press 2nd, THEN Y=. In the STAT PLOTS MENU choose Plot 1; turn the plot on by pressing ENTER. Choose the scatter plot (first graph) on the TYPE row and then press ENTER. Press ZOOM 9.)

1. Remove the link cables from the voltage probe, place the link cable on the zinc rod of the cucumber and connect it to one side of the LED. Place the link cable on the copper rod of the pickle to the other side of the LED. If the LED does not light up switch the cables to the opposite side. When connected properly the LED will light up.

1. Complete the questions and analysis on the worksheet.

A VEGETABLE A DAY WILL LIGHT YOUR

Name Date______Group # ______

1. Use your data that you have obtained and fill in the chart below. Do not forget your units.

VEGETABLES

/

VOLTAGE (v)

1.Cucumber

2. Potato

3. Onion

4. Tomato

5. Pickle

1. Draw your own line graph. Be sure to label your graph, plots the points on the graph, and trace your points. (There is an extra grid in case you mess up)

1. Which vegetable conducted more electrical current and which conducted less? Explain. (To get an individual vegetable reading, subtract the vegetable voltage reading from the previous vegetable voltage reading)

4. Explain how the use of vegetables light up the LED (light emit dio).

Lab Report: A VEGETABLE A DAY WILL LIGHT YOUR WAY
Teacher name: Kaye Thibodaux - Carla Ortego
Student Name ______
CATEGORY / 4 / 3 / 2 / 1
Participation
SCORE ______/ Used time well in lab and focused attention on the experiment. / Used time pretty well. Stayed focused on the experiment most of the time. / Did the lab but did not appear very interested. Focus was lost on several occasions. / Participation was minimal OR student was hostile about participating.
Procedures
SCORE ______ / Procedures are listed in clear steps. Each step is numbered and is a complete sentence. / Procedures are listed in a logical order, but steps are not numbered and/or are not in complete sentences. / Procedures are listed but are not in a logical order or are difficult to follow. / Procedures do not accurately list the steps of the experiment.
Analysis
SCORE ______/ The relationship between the variables is discussed and trends/patterns logically analyzed. Predictions are made about what might happen if part of the lab were changed or how the experimental design could be changed. / The relationship between the variables is discussed and trends/patterns logically analyzed. / The relationship between the variables is discussed but no patterns, trends or predictions are made based on the data. / The relationship between the variables is not discussed.
Drawings/Diagrams
SCORE ______ / Clear, accurate diagrams are included and make the experiment easier to understand. Diagrams are labeled neatly and accurately. / Diagrams are included and are labeled neatly and accurately. / Diagrams are included and are labeled. / Needed diagrams are missing OR are missing important labels.
Journal/Notebook
SCORE ______ / Clear, accurate, dated notes are taken regularly. / Dated, clear, accurate notes are taken occasionally. / Dated, notes are taken occasionally, but accuracy of notes might be questionable. / Notes rarely taken or of little use.
Data
SCORE ______/ Professional looking and accurate representation of the data in tables and/or graphs. Graphs and tables are labeled and titled. / Accurate representation of the data in tables and/or graphs. Graphs and tables are labeled and titled. / Accurate representation of the data in written form, but no graphs or tables are presented. / Data are not shown OR are inaccurate.
Question/Purpose
SCORE ______ / The purpose of the lab or the question to be answered during the lab is clearly identified and stated. / The purpose of the lab or the question to be answered during the lab is identified, but is stated in a somewhat unclear manner. / The purpose of the lab or the question to be answered during the lab is partially identified, and is stated in a somewhat unclear manner. / The purpose of the lab or the question to be answered during the lab is erroneous or irrelevant.
Conclusion
SCORE ______/ Conclusion includes whether the findings supported the hypothesis, possible sources of error, and what was learned from the experiment. / Conclusion includes whether the findings supported the hypothesis and what was learned from the experiment. / Conclusion includes what was learned from the experiment. / No conclusion was included in the report OR shows little effort and reflection.

TOTAL SCORE______

SAMPLE DATA

Voltage Data Voltage v/s number of vegetables

Cucumber .564 v Cucumber and potato 1.379 v

Cucumber, potato, and onion 2.274 v Cucumber, potato, onion, and tomato3.149v

Cucumber, potato, onion, tomato, and pickle 4.024 v

Individual voltage reading:

Cucumber- .56 v Tomato- .91 v

Potato- .82 v Pickle- .88

Onion- .90 v

References:

1. Louisiana Department of Education (1997). Louisiana Science Framework,

Retrieved December 13, 2001, from the Louisiana Department of Education

Website.

1. Johnston, Ellen C. and Young, David A., Data Collection Activities for the Middle

Grades with the TI-83, CBL, and CBR, Texas Instruments Incorporated 1999.

1. Calculator and CBL experience received from the LaSIP program at Nicholls State

University with Dr. Judy Chauvin, Project Director.

4. Rubric adapted from