Coloring Agents of Fireworks
Names:
Natalie Pickering
Title of Lessons:
Metals--Flame Test (Investigation Type Lesson)
Date of Lesson:
April 21st , 2005
April 24th , 2005
Length of Lesson:
2 days
Description of the Class:
Name: Chemistry
Grade Level: Sophomore
Schedule: Blocked (80 minute class)
Source of Lesson:
Natalie Pickering
Mr. Emry (my high school chemistry teacher)
http://www.pbs.org/wgbh/nova/kaboom/elemental/
TEKS Addressed:
(1) Scientific processes. The student, for at least 40%
of instructional time, conducts field and laboratory investigations using safe, environmentally appropriate, and ethical practices. The student is expected to:(A) demonstrate safe practices during field and
laboratory investigations; and(2) Scientific processes. The student uses scientific
methods during field and laboratory investigations. The student is expected to:(A) plan and implement investigative procedures
including asking questions, formulating testable hypotheses, and selecting equipment and technology;(D) organize, analyze, evaluate, make inferences,
and predict trends from data; (E) communicate valid conclusions.(4) Science concepts. The student knows the
characteristics of matter. The student is expected to:(D) describe the physical and chemical
characteristics of an element using the
periodic table and make inferences about its chemical behavior.
Students construct and perform investigations to determine various unknown metal ions found in fireworks. Students must analyze their results and share their conclusions with the class. Students are then given time to research the Internet (specific sites are provided) to find the theoretical colors produced by those certain metal ions. A formal lab report will be turned in by the end of the week.
The student will be able to:
á Develop a testable procedure for their coloring agent investigation.
á Construct a data table that is appropriate for their lab
á Investigate the MSDS and safety information concerning the chemicals they will be using.
¯ Altered Anchor Video
¯ Students lab notebooks
¯ 30 Flame Test lab sheets
¯ Computers with Internet access
¯ Website: http://www.pbs.org/wgbh/nova/kaboom/elemental/
Safety
Considerations
Students will not be using the chemicals today, but must become aware of their safety data.
Anchor Video
Convert the Anchor Video firework pictures to black and white clips.
Modified 5E Model:
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Engagement: Time: 8:30—8:45 AM Show the anchor video again, but these times have all the pictures that have fireworks in black and white. Before you play the video tell the students that something has changed from the last time they saw the video, and they must individually identify the difference. Play the video. Call on a student to tell you whatÕs has changed from the first video to the second? Did any one see any other difference? Correct, today begins a new section of the chemistry of fireworks, the coloring agent! (write this term on the board!) Pre-Assessment: (quick oral quiz) What exactly is a coloring agent? How is the color produced during the explosion of the firework? How does chemistry have to do with coloring agent? The only answer that needs to be given is that the coloring agent has something to do with metals. |
Students ready to take the challenge of discovering what is different in this video. Students watch, and quickly realize that there is no color in any of the fireworks. Student replies that the fireworks donÕt have any color. No Students will give various answers. á Their prior lesson on the history of fireworks has taught them that the coloring agent is a metal compound. á Color is produced from: I donÕt know, burning the metal, reacting it with something else. á The chemistry has to do with the electrons, molecules, etc. A chemist can make the compound that is used to give color. |
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Exploration: Time: 8:45-9:35am ÒSo we know the main ingredient in the coloring agent is a metal. But look at the periodic table, there are lots of metals that could be used to give color. How do we know which metal gives a certain color? Say we had a firework that makes a red burst in the sky, what metal was in itÕs coloring agent? What about a purple, green, yellow, etc. firework?Õ Tell the students that they are determine a way to test what metal is the coloring agent of a firework given the following equipment: wire frame-loop, Bunsen burner, various metal nitrates (7 known and 4 unknown) Have students get into their lab groups and come up with a testable procedure (doesnÕt have to be exact or too detailed) and the data table they will use to collect their data. Once groups have developed a procedure and data table (and been approved by the teacher) they should go to a computer and research the MSDS and safety data concerning the nitrates they are going to use. They must write down in their laboratory notebooks the usual asked for information. All-in-all, students must have their pre-labs ready for tomorrowÕs lab. The usual requirements are: Title, purpose, table of chemicals, procedure, data table. Each student needs to have his or her own pre-lab. They can reference the procedure given to them in the handout. (remind them of pre-lab quizzes). Walk around the classroom and check in with groups. Ask them the following guiding questions: á How do you know which metal makes what color? á How can you determine the unknown colors? á Is there a certain order to test the metals? á How are you going to clean the wire loop? á Are you going to use any resources such as books, periodic table, etc?
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Possible Student responses:
Students listen Students work together in lab groups on developing procedure and data table. Students use computers to research the MSDS information needed. They write this in their pre-lab information which will be checked tomorrow before they begin the lab. Groups answer:
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mini-Explain: 9:30-9:55am Instruct groups to finish up what they are doing. Have groups get up and discuss their procedure and data tables they created. Other students should give comments/suggestions to these. Pass out the actual Flame Test handout, which contains a procedure as well as some useful background information (hopefully studentsÕ procedures will be similar). Briefly go over the actual procedure students will follow and the safety rules. Remind students to have their pre-labs ready for tomorrowÕs lab. Students should more carefully read the handout at home. |
Students present their procedures and data tables while other students listen and then give comments/suggestions. Students look over the handout. Students watch the brief demonstration of the lab, and they listen to safety guidelines. |
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mini-Evaluation: 9:55-10:00am As students leave check to see that they have written down components needed for their pre-lab (a check to make sure they were working today). Their official pre-lab should be ready by Monday. Assignment: CAT: Students are to read the handout over the weekend. By Sunday, they need to have emailed the teacher with a brief Òmurkiest pointÕ paper. |
Students show teacher the work they have done all period. Students have the weekend to read the handout and write a Ômurkiest pointÕ paper. |
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2nd DAYÕS LESSON (April 11th)
Students will be able to:
á Identify unknown metal ions through the use of a Flame Test.
á Explain and justify their conclusions to the class.
á Critique the procedure and results of the Flame Test.
á Determine a pattern among metal ions and their position in the periodic table.
Per Student:
¯ Safety goggles
¯ Protective apron
¯ Lab Handout
¯ Lab Notebook
¯ Pen or pencil
Per Lab Group:
¯ Wire flame-loop
¯ Bunsen Burner
¯ 2 small beakers
¯ 6.0M hydrochloric acid
¯ distilled water
Per Student Pair
¯ Computer with Internet access
Per Class:
¯ Set of beakers containing metal nitrates:
á Barium Nitrate
á Potassium Nitrate
á Calcium Nitrate
á Lithium Nitrate
á Copper Nitrate
á Strontium Nitrate
á Sodium Nitrate
á Unknown Metal Ion #1, #2, #3, #4 (K, Sr, Ba, Li)
Lab Sheet (students got yesterday)
Advance
Preparation:
Have lab material ready to be distributed. Chemicals should be kept up front at teacherÕs desk.
Lesson
Organization
Teacher
Does Students
Do
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Explore Continued 8:30-9:10am Teacher goes over murkiest points. Teacher tells students they have 30 minutes to work on the Flame Test Lab. Teacher walks around checking in on students and asking prompting questions: á What colors are you seeing? á Any patterns in the colors seen and the placement of the metal on the periodic table? á How do we know that the Nitrate isnÕt contributing to the color? á Is orange and orange red the same? á Does your partner see/describe the color like you do? How are your observations different? á What are the unknown metals? How do you know? After 30 minutes instruct students to start cleaning up lab and get ready for discussion. |
Students listen as questions they had are answered. Students get into lab groups and work on the lab. Students answer:
Students clean up their lab stations. |
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Explain: 9:10-9:35am Teacher leads a class discussion about what students observed. She calls on random students to identify the unknown metal. Other students are encouraged to speak up if they got different results. Can even call on students to state the flame colors they observed for certain metal ionsÉillustrating the subjective ness. This leads to a discussion of the accuracy of the Flame Test method. How can we be so sure that the results we got are good? |
Students give identify of the unknown metals. Some students may have gotten different identities based on differences in colors seen. Students state the colors they got:
Students think about the inaccuracies involved in using flame tests for identification purposes.
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Extension: 9:40-10:00am Students work individually or in pairs researching the web. (teacher provides the sites) They are to compare the results found on the internet with the results they got. Turn in the researched data with their final lab report. Teacher walks around making sure students are on task. If students have timeÉask them to think about and/or research why different metals have different colors |
Students researching websites. Students write up Ôtheoretical results.Õ |
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Evaluation: Students are to turn in their lab report by Wednesday. Teacher dismisses class |
Students turn in their completed lab reports. Students leave |