Lida Schoen
Education Consultant Amsterdam, Netherlands, former member CCE

Mei-Hung Chiu
National Taiwan Normal University, Taipei, Taiwan, chair CCE

Abstract

For many years the authors collaborated with Prof. Fortunato Sevilla III. This paper relates hightlights of our collaboration in the Philippines and on the world, mainly on the Young Ambassadors for Chemistry (YAC) and the Flying Chemists Program FCP projects, supported by the Committee on Chemistry Education (CCE) of the International Union of Pure and Applied Chemistry (IUPAC).

Introduction

The Committee on Chemical Education is one of the standing committees of the International Union of Pure and Applied Chemistry (IUPAC). It is tasked to coordinate the educational interests of the IUPAC bodies with activities throughout the world. Among the activities of the Committee on Chemical Education of the International Union of Pure and Applied Chemistry (IUPAC) are the Young Ambassadors for Chemistry (YAC) and the Flying Chemists Program (FCP).

The Young Ambassadors for Chemistry (YAC) [1] is a project that has trained teachers across the globe to help students communicate the benefits of chemistry and enhance the public understanding of chemistry. A typical YAC event encompasses two to three days of teacher workshops, followed by a half-day public event where students – the Young Ambassadors for Chemistry – share their enthusiasm and interest with the public. It was a collaboration between the Science Across the World (SAW) Programme [2] and the International Union of Pure and Applied Chemistry.

The Flying Chemists Program (FCP) [3] is an initiative that aims to provide emerging countries with the means to improve the teaching and learning of chemistry at primary, secondary and tertiary levels. The project provides the visited country with the expertise needed to strengthen chemistry education and to assist in its development.

Though the IUPAC does not have a National Adhering Organization from the Philippines, we were able to conduct activities in this country. The proposal submitted to IUPAC by Prof. Fortunato Sevilla III paved the way for us to collaborate with the local efforts to improve the teaching and learning of chemistry in the Philippines.

2008: Philippines
Flying Chemists Program: Improving Chemical Education

Prof. Sevilla organized the 3rd FCP as a conference on ‘Improving Chemical Education’ in Manila, with additional support from the Commission on Higher Education (CHED) and the University of Santo Tomas. The conference was designed to introduce innovative instruction for tertiary level chemistry teachers.

Over 300 tertiary level chemistry teachers from all over the country participated in the conference. The total number of the audience was far beyond expectation and video conferencing was arranged to accommodate all participants [4].

There were five keynote speakers and three workshops during the 2-day conference. Peter Atkins (Lincoln College, Oxford, UK) presented marvellous pictures to show how pictorial representations can help students learn complex concepts in stoichiochemistry. Peter Mahaffy (King’s University College, Edmonton, Canada) gave a vivid talk on visualization impact on learning introductory chemistry at the undergraduate program in his university and also held a workshop on visualizing chemistry. Jorge Ibáñez (Universidad Iberoamericana, Mexico City, Mexico) showed the audience how to use microscale laboratory experiments to achieve instructional effectiveness. He reduced the amount of the chemicals for green chemistry in his talk and workshop. Fortunato presented how to make good use of low cost microscale experiments and provided a hands-on low-cost workshop. Mei-Hung Chiu reported on the effectiveness of an integrated laboratory program for students at the National Taiwan Normal University via the use of a valuable and easy-to-apply quantitative assessment in the organic chemistry laboratory.

The conference went successfully with the affirmative feedback from the participants. They highly appreciated Prof. Sevilla’s effort on organizing the conference to promote chemistry education in the Philippines.

2010: Philippines
25th Philippine Chemistry Congress: Creating Green Solutions through Chemistry

Our participation in the 25th Philippine Chemistry Congress allowed us an opportunity to interact with Filipino chemists and chemistry teachers during their annual gathering. We were among the overseas speakers who were invited to Subic Bay to present papers to the Philippine chemistry community. We were hosted by the Philippine Association of Chemistry Teachers, which was led by Prof. Myrna Rodriguez as president.

We presented our keynotes during the Symposium on Chemical Education. After lunch Mei-Hung started with ‘Learning and Teaching with a Model based Approach to Chemistry Education’. The keynote was followed by three 20- minute presentations, with one outstanding about the use of portfolios in secondary education. After a long interval for networking and attending the poster session, Lida presented ‘Chemistry around the World, Educating Secondary School Students as Global Citizens’, also followed by a most interesting 20 minute presentation about a camera used as a colorimeter.

After another full conference day we enjoyed our dinner with ocean view with interesting discussions with Fortunato and Maribel (Nonato, president of the Philippine Chemical Society) about a career for women. The situation looks like the same all over the world!

We were requested to give a short presentation during the closing ceremony: Mei-Hung about the International Conference on Chemical Education (ICCE 21) which was to be held in Taipei on August 2010, and Lida about the coming YAC course/event in Manila.

The bus took us back to Manila. On our way we enjoyed a huge farewell ice cream!

2010: Philippines
Young Ambassadors for Chemistry, in Manila

Prof. Sevilla took the initiative to host YAC in the Philippines, through the Philippine Association of Chemistry Teachers (PACT), chaired by Prof. Myrna Rodrigues. PACT organised and facilitated the YAC course at the Asian-Pacific College, FUSE-LCT (Foundation for the Upgrading of the Standard of Education – Learning Center for Teachers) and the event in the Manila ShoeMart shopping mall.
40 teachers and 60 students from 15 public and secondary schools from Metro Manila and nearby provinces and from as far as Davao City, participated in the YAC program.

Dr. Norietta Tansio of the PACT officially opened the course. After the break (with wonderful food, being common practice during all coming breaks) we introduced the Young Ambassadors for Chemistry project. After lunch Prof. Sevilla presented a short welcome speech. The teachers received a wonderful course book with the YAC program, background information and a nice metal YAC button.

The next morning in the FUSE building we carried out practical (group) work, that generated a great deal of hilarity and the presentation of the creative statistical group results. After lunch the teachers started the practical YAC work: design and produce a innovative cosmetic line with 4 products: perfume (for men), hair gel, shampoo and lotion. The very well organized workshop resulted in great products and again a lot of fun during the 30 seconds TV commercials of the different groups to sell the cosmetics.

During our last morning in the FUSE building, we divided coordination roles for the YAC event with the students. As the organizers already prepared so much, we could quickly finish.

The main YAC activity was held in the ShoeMart Shopping Mall (SM) Manila. SM Manila was a real great location for a YAC event: many shoppers around, a climatized open space and all facilities available.

All students, teachers and organisers wore a YAC T-shirt with the YAC logo and a YAC button. We were clearly audible: Nori and 3 disc jockeys produced a lot of ‘noise’ and also clearly visible: branding with YAC balloons and spotlights on the stage from the higher floors around the open space. Everything went smoothly with students, teachers, chemicals and stationary! The chemicals coordinators did their jobs, while the roving reporters coordinators sent the students out to question the public about their views on chemistry and learning chemistry. They wandered around in the shopping mall, asking the public 3 questions.

Next step was to take the public to their work stations, show them their work and ask three more questions. After swapping roles, the students ran out of questionnaires completely after handing out 100 copies. Mei-Hung took all questionnaires back to Taiwan to analyse answers from the public and the students and also of the participating teachers (filled in at the end of the course).

We asked the participating teachers (N=34), students (N=52) and the public (N=98) to fill in our questionnaires on the quality of the workshops, hands-on activities and their image of chemistry.

The majority of the teachers (98%) enjoyed the workshops very much and expressed that learning incurred through the workshop. The results from the students were similar. Their responses revealed the design of the cosmetic experiments were appealing and educational. These views were also evident from the responses of the public: positive feedback on the chemical experiments and high value about the role of chemistry in society.

As for their images of what chemists are doing, we asked all participants ‘Which of the following pictures shows what you think about chemistry best?’ The results of their responses are shown below (5 points for best and 1 point for least). We found that all 3 groups considered the 2nd picture to be the best representation of chemistry, followed by the 3rd picture. This outcome was considered to be the positive image of chemistry with appropriate manipulations of equipment with peers, unlike the negative images, such as boring in picture 1, incorrect operation of chemicals in picture 4 or a negative image (explosion) in picture 5.

We were very honoured to have National Scientist and 2010 UNESCO-L’Oréal Laureate for Women in Science Prof. Lourdes Cruz with us! Together with Dr. Imelda Servillon (Science Supervisor of the Division of City Schools-Manila, Department of Education) and Prof. Cristina Binag (University of Santo Tomas) she agreed to form our distinguished jury. The jury judged the quality of the product lines and the public presentations of the student groups.

At the end of the event all involved received a certificate of attendance with the signatures of IUPAC’s president Nicole Moreau and SAW’s director Marianne Cutler. This was the end of another glorious day with students and teachers promoting chemistry during our 10th international Young Ambassadors for Chemistry event!

2011: [Global] International Year of Chemistry: The Global Stamp Competition

Headed by Lida Schoen (IUPAC, CCE, Netherlands) the Global Stamp Competition , competition [5,6] was launched in Paris on January 2011 during the IYC 2011 opening ceremony at UNESCO Headquarters. The theme of the competition was ‘Chemistry as a Cultural Enterprise’ (CCE), entries were required to highlight the impact of chemistry on a country’s culture and everyday life [7]. Designs were judged for their artistic value, how well they showed the relationship between chemistry and the national/regional culture and the quality of the description.

The main challenge for the organizer, apart from obtaining funding (IUPAC Committee on Chemistry Education and GlaxoSmithKline), was the difficulty of making students / teachers / professors aware of this competition in a timely manner. Publishing on different sites (IYC 2011, IUPAC, Science Across the World [8]) was not effective. Apparently students and teachers don’t pay attention to these media. Next interviews and publications in journals of chemical societies and chemistry teachers associations were tried with little more effect. But the most successful were personal global contacts like with Prof. Sevilla! He turned the competition into a class activity for freshmen. Apart from many quality submissions this generated a lot of valuable peer review.

The competition benefited greatly from social media: the site students used to upload their submissions allowed for sharing comments and reviews. In so doing, the competition itself became a social and cultural enterprise. In fact, among the criteria used by the judges were the number of hits and number and quality of the peer reviews on the site.

After 6 months and 247 submissions from 18 countries in 3 age categories, an international jury with Prof. Morton Hoffman (CCE NR USA, ACS), Dr. Rachel Mamlok-Naaman (CCE NR Israel), Dr. Lynn Hogue (ACS), Datuk Dr. Soon Ting Kueh (CCE NR Malaysia, IKM [9], FACS), Dr. Anthony Smith (EC2E2N [10]), Dr. Harry Kelly (GlaxoSmithKline) and Prof. Daniel Rabinovich (USA, stamp expert) announced the winners of the International Year of Chemistry Global Stamp Competition.

• 12–14 age group: Vasilena Vasileva (14) from SOU Hristo Botev, Gorna Malina, Bulgaria
• 15–18 age group: Muzhafar Hassan Ismail (17) from MARA Junior Science College, Taiping, Malaysia
• Runners Up in the 15–18 age group: Stavrou Maria, Spyrou Chrisia, and Stylianou Chrysovalento (Cyprus); Luqman Safwan Che Mohd Fauzi (Malaysia); Kyle Stratford and Max Willinger (USA)
• Undergraduates: Peter Yousef M. Rubio (18) from Santo Tomas University, Manila, Philippines

Peter Yousef Rubio’s winning design was presented during the Coconut Week Celebration of the Philippine Coconut Authority-Department of Agriculture in Manila, Philippines and he was invited as guest of honour during the Annual Conference of the Philippine Chemical Society.

Due to a generous gift of GlaxoSmithKline the winners received $500 and the runners up $250 (for the group). A selection of the best designs was on display during the IYC Closing Ceremony in Brussels in December 2011.

2012: Central America (Panama and Mexico) YAC and FCP in Panama City

At the Congreso Latinoamericano de Quimica (CLAQ 2012) held in Cancún, Mexico in October 2012, several IUPAC activities related to projects of the Committee on Chemistry Education (CCE) were organized. These included the Flying Chemists Program (FCP, Mei-Hung) and the Young Ambassadors for Chemistry (YAC, Lida) project. Taking advantage of the geographical proximity, the activities were first showcased in Panama [12].

Panama City
In October 2012 the Ministry of Education of Panama and the Universidad de Panama hosted Lida, Mei Hung and Fortunato (Flying Chemists task group member). Lida organized with help of Mei-Hung and Fortunato a YAC workshop with 25 participants and a public event in front of the Ministry of Education offices with over 100 student participants. Local organizers included Marisa Talavera of the Ministry of Education and Abdiel Aponte and his group from the Universidad de Panama.

As the organisers in the Ministry did not exactly know who was who and having not enough chairs behind the table, ‘poor’ Fortunato, as the only CCE male, had to present YAC.

The course and the event went very well with receptive teachers and enthusiastic creative students! Very special was the tropical storm rain during the lunch break that emptied loads of rain on our (covered) outside venue! During the morning and afternoon event we could never have managed without all dedicated trained teachers, despite a few language problems.

For the Flying Chemists Program we presented 3 workshops to high school and college teachers:

• Mei-Hung: Models and Modelling
• After a short introduction all students produced a C20 (pentagons), quite a few of them even managed to finish a C60 (pentagons and hexagons).
• Mei-Hung: Alternative Ways of Assessment
• Lida: Communicating Chemistry, Teaching as the Most Difficult Job in the World Explained.
• Fortunato: Microscale Analytical Chemistry Experiments Based on Low-Cost Instrumentation

Cancún, Mexico
In connection with CLAQ 2012 [13], the Sociedad Quimica de Mexico and the Federacion Latinoamericana de Sociedades de Quimica hosted and facilitated the YAC and FCP workshops. Peter Mahaffy (King’s University College, Edmonton, Canada), CCE past chair) joined the CCE group.

In the morning the FCP program offered 3 hands-on workshops:

• Alternative Diagnostic Assessment in Chemistry Education, Mei-Hung
• Using the Rich Context of Climate Science to Teach Chemistry, Peter Mahaffy
• Microscale Analytical Chemistry Experiments Based on Low-Cost Instrumentation, Fortunato

The workshops were attended by high school and college teachers from throughout Latin America (at an average of 20 participants in each). Kazuyuki Tatsumi (IUPAC president), Cecilia Anaya (SQM president) and Héctor Cárdenas (SQM general secretary) welcomed participants at the beginning of the workshops. The local organizer Jorge Ibáñez (Universidad Iberoamericana, Mexico City and SQM) had much assistance from Carlos Ruis Alonso (Universidad Nacional Autonoma de Mexico and SQM).

During the afternoon the group participated in the Symposium on Chemistry Education, which about 100 persons attended. Organized by Jorge Ibáñez, the symposium included the following 30 min. presentations:

• Alternative Diagnostic Assessment in Chemistry Education, Mei-Hung
• Using the Rich Context of Climate Science to Teach Chemistry, Peter Mahaffy
• Communicating Chemistry, the importance of language, Lida
• Analytical Chemistry Experiments in Microscale, Fortunato
• Teaching Environmental Chemistry through Experiments, Jorge Ibáñez

The same day, the group participated in the YAC event at which several hundred people took part in the outreach activities. The YAC event took place in front of the town hall Benito Juarez of Cancún, a spacious square.

On the days prior to the public event, the usual YAC training workshop was held. Héctor Cárdenas kicked off the YAC training workshop, which, instead of training teachers, was focused on chemistry and medical students. No one knew how many students to expect for the event, nor from where they would come.

Unstructured groups of students descended upon the square, filled up with a huge Periodical System around iron frames, that we used as tables for the experiments. Our 8 volunteers did what they could to contain what appeared to be a chaotic situation, but which was simply a popular event with a lot of enthusiastic students and members of the public. Visitors to the event included Cecilia Anaya (president SQM), Nicole Moreau (past president IUPAC), Kazuyuki Tatsumi (president IUPAC), Javier García-Martínez (AM CCE, IUPAC Bureau) and Miranda Wu (president ACS). A local policeman estimated there had been 1000 visitors throughout the day on the square.

Conclusion

Within the IUPAC Committee on Chemistry Education it has been a privilege and a great pleasure to collaborate with Prof. Fortunato Sevilla III. We wish him many more healthy years to continue his beneficial and successful work in the Philippines and elsewhere on the Globe.

References

1. CCE project proposal ‘Research-based evaluation of the Young Ambassadors for Chemistry project’: https://www.iupac.org/nc/home/projects/project-db/project-details.html?tx_wfqbe_pi1%5Bproject_nr%5D=2007-005-2-050 (last accessed October 2013)
2. Science Across the World website: https://www.scienceacross.org (last accessed October 2013)
3. CCE project proposal ‘FCP Philippines’: https://www.iupac.org/nc/home/projects/project-db/project-details.html?tx_wfqbe_pi1%5bproject_nr%5d=2007-018-1-050 (last accessed October 2013)
4. Fortunato B. Sevilla III, Report Improving Chemical Education in the Philippines, Chem. Int. 30, 4 (July- Aug 2008): https://www.iupac.org/publications/ci/2008/3004/cc2_170408.html (last accessed October 2013)
5. Editor Chem. Int., Chemistry International, 33, 6 (Nov-Dec. 2011) The Global Stamp Competition: https://old.iupac.org/publications/ci/2011/3306/8_stamp_competition.html (last accessed October 2013)
6. Lida Schoen, ConfChem Conference on A Virtual Colloquium to Sustain and Celebrate IYC 2011 Initiatives in Global Chemical Education: Global Stamp Competition, J. Chem. Educ., Publication Date (Web): October 8, 2013 (Communication). https://pubs.acs.org/doi/abs/10.1021/ed300878w?prevSearch=%255BTitle%253A%2BGlobal%2BStamp%2BCompetition%255D&searchHistoryKey (last accessed October 2013)
7. IYC 2011 Global Stamp Competition project idea: https://www.chemistry2011.org/participate/activities/show?id=110 (last accessed October 2013)
8. Science Across the World Facebook group: https://www.facebook.com/groups/108632725863761/ (last accessed October 2013)
9. IKM: Institut Kimia Malaysia.
10. EC2E2N: European Chemistry and Chemical Engineering Education Network
11. Countries with 1 or 2 submissions: Bulgaria, Colombia, Cyprus, France, India, Indonesia, Lithuania, Puerto Rico, Ukraine
12. Editor Chem. Int., CCE Projects in Latin America (May-June 2013), Chem. Int. 2013, 34, 5: https://www.iupac.org/publications/ci/2013/3503/pp1_CCE_projects.html (last accessed October 2013)
13. CLAQ: Latin American Chemistry Congress

Mickey Sarquis1* and Lynn Hogue2
Terrific Science, USA

1 Professor Emerita Department of Chemistry & Biochemistry and
Director Emerita Center for Chemistry Education, Miami University, Ohio, USA
Present address: 1514 Lupine Rd, Healdsburg, CA 95448 USA,
1-707-395-0260 (home)
SarquiAM@MiamiOH.edu

2 Retired Associate Director, Center for Chemistry Education, Miami University, Ohio, USA
LynnHogueTS@gmail.com

Abstract

One of the most important aspects of teaching any science is to convey the methodology of scientific investigation in such a way that students develop the skills that are fundamental to scientific inquiry and the scientific way of processing information. As students develop their own testable questions about the system being studied, design experiments, collect data, formulate claims that can be substantiated by the evidence, develop multimodal models to represent this understanding, and subsequently share these with others by engaging in open discussion, debate, and scientific argumentation, students become immersed in the scientific endeavor. In the process, students learn to reflect on this discourse and come to challenge their preexisting beliefs and refine their original claims as new evidence becomes available. Examples of these strategies are shared in this paper.

Key Words: Claims and evidence; Chemical education

Introduction

As chemistry educators who have been touched by Professor Fortunato Sevilla III, we share his drive to inspire, motivate, and share our mutual enthusiasm for chemistry with our students, colleagues, and the general public. We aspire to capture the attention of others by providing positive energy, exuberance, and even certain “magnetic” qualities that are embodied in the charisma of chemistry.

My dear young friends, If I were to present myself before you with an offer to teach you some new game—if I were to tell you an improved plan of throwing a ball, of flying a kite, or of playing leapfrog, oh, with what attention you would listen to me!

Well, I am going to teach you many new games. I intend to instruct you in a science full of interest, wonder and beauty; a science that will afford you amusement in your youth, and riches in your more mature years. In short, I am going to teach you the science of chemistry.

– Professor John Scoffern, 1849, Chemistry no Mystery

A wide variety of actively engaging experiences empowers students to gradually formulate their own understandings about abstract, complex chemical systems. As teachers, we need to make sure we are not dissociating fun, hands-on play from minds-on challenges. We need to broaden our teaching repository by interweaving diverse instructional methods to target different learning styles and engage different parts of the brain. We also need to support our students’ learning by helping them identify misconceptions, by asking higher-level questions, and by providing a safe environment that encourages students to think critically and take risks.

Developing Understanding with Claims and Evidence

One of the most important aspects of teaching any science is to convey the methodology of scientific investigation in such a way that students develop the skills that are fundamental to scientific inquiry and the scientific way of processing information.

While process skills such as observing, sorting, and classifying are important life skills that transcend the discipline of science, science is more than this set of skills; it is a way of looking at, learning about, and interacting with the world. Scientists ask questions, investigate systems, develop methods, and collect data. Next, scientists use information gathered through these actions to formulate claims that can be substantiated by their findings and subsequently shared with the larger community, allowing for open discussion, debate, and scientific argumentation. Scientists must be willing to reflect on this discourse and refine their original claims as new evidence becomes available. The open nature of scientific discourse provides an important safeguard in scientific endeavors.

Students need numerous opportunities to build these skills and experience this process in total. Through experience, the scientific method becomes more than a list they memorize from a textbook, but rather a working system that is an integral part of their lives. Teachers can maximize student learning by selecting meaningful experiences that grab student’s attention, challenge their preexisting beliefs, and encourage the development of testable questions. Careful observation plays a key role in the process as a catalyst for raising questions and as a means to gather evidence. Students will need to think about what they are observing, discuss their observations with peers, ask questions about what they are seeing, and reflect upon their observations.

Let’s consider three different commonly available toys: light sticks (available in a wide array of sizes, colors, and styles available from toy, novelty, and fishing/hunting suppliers), light-sensitive paper (sold commercially under the brands Nature Print® and Sunprint®), and UV-sensitive beads (often described as color-changing beads, are sold by many science and craft suppliers) and see how can students can be engaged in the claim and evidence learning approach to the scientific method as they discover the basic chemistry of these common toys. We would typically recommend that you have the whole class focus on just one of these systems at a time, working in small groups. In this way, students discover a great deal about each system through their own work and by hearing other groups’ observations, questions, and results. Later, by repeating the entire process for the other systems, students gain critical practice applying the methodology of scientific investigation to a series of different questions.

To begin students are asked to explore the assigned system and record their observations. In some cases the materials include instructions for use. If so, students should begin by following those instructions. (This step is especially important for the light-sensitive paper, because without initial instructions, discovering the properties of the paper would be quite difficult.) After the students have explored the system, allow time for discussion. Compiling a list of observations as well as comments and questions is often helpful.

Once students have explored a material, have them work in small groups to decide what else they would like to know about their system. Suggest they think about questions that start with “What would happen if…” Once each group of students has identified and listed some possible questions, have them choose one specific question to explore and design an experiment that could answer this question. Depending on your students’ experience, you may want to structure their work by asking them to answer questions such as the following:

• What is your testable question?
• Is there something you observed about your system that led you to ask this question?
• What materials will you need for your experiment?
• What data will you need to gather in order to provide evidence to answer your question?
• What tools and methods will you use to collect this data?

While we strongly recommend that students develop and investigate their own testable questions, teacher may need to seed the discussion with possible questions particularly when students are new to the methodology. Some examples of testable question might include the following:

• light sticks—How does temperature affect the activated light sticks? Does wrapping a light stick in insulating materials before activating it affect its glow? Do different sizes, colors, or shapes of light sticks last for the same amount of time or emit the same amount of light?
• light-sensitive paper—What effect does a translucent object’s color have when exposing light-sensitive paper? What about objects with different opacities?
• What is the effect of exposing the paper using different types of light sources such as UV, fluorescent light, or light-emitting diodes (LEDs)? What about different colors of light? When exposing the paper to direct sunlight, does the time of day matter? What about the duration of exposure?
• UV-sensitive beads—What happens if UV-sensitive beads are covered with sunscreen of various sun protection factor (SPF) values? What if the beads are covered with fabrics of different opacities? How about sunglasses with various UV ratings? Does clear plastic or glass give a different result than a sunglass lens? What is the effect of exposing the beads using different types of light sources such as UV, fluorescent light, or LEDs? What about different colors of light? How do different colors of LEDs affect different colors of beads?
• Does changing the temperature of the beads affect how long it takes them to change back to white?

Teachers are encouraged to review and approve the proposed experiments before students proceed or set limits in advance based on availability of materials, time constraints, or other classroom management issues. Emphasize that the goal is to collect data that will provide evidence that allows the testable question to be answered. Note that data, along with the interpretation of that data, provide the evidence. As students are working, you may hear comments such as “This isn’t working,” or “My results are wrong.” Evidence is what it is, and the results may be unexpected. Sometimes, no noticeable change occurs in an experiment, and this is valuable information. Depending on the questions being explored, digital photos or movie clips may be a useful form of data for students to collect.

When the experiments are complete, ask students to share their claims and the evidence for their claims and defend them with the rest of the class. Much like the practice in the scientific community, the class is encouraged to openly discuss, debate, and engage in argumentation about the presented evidence. Students must then reflect on this discourse and refine their original claims.

Allowing students to ask and strive to answer their own questions gives them a much bigger stake in the outcomes of their investigations, which in turn leads to improved conceptual understanding.

Because this experience is so important to students’ growth as scientists, we hope you can work such sharing into your schedule. As an alternative to verbal presentations, students can be asked to write a position statement presenting their claim and their evidence for it. These papers could be peer-evaluated for clarity, strength of argument, and other evidence the peer-evaluator might be aware of. Other options include students participating in poster sessions; writing informative letters to their families, younger students, or the school board; or developing PowerPoints or YouTube-style videos. By providing these experiences you will help your students become stronger communicators, an important skill in all careers.

The Chemistry of Our Examples

Light sticks consist of a sealed plastic tube that contains two solutions. One solution is in a thin glass vial within the plastic tube. The light stick is activated by bending the plastic tube, breaking the glass vial so the two solutions can mix. When mixed, the two solutions react, producing light.

The glass vial contains hydrogen peroxide (H2O2), and the solution in the plastic tube contains a fluorescent dye and a phenyl oxalate ester. The ester and H2O2 react first, producing an intermediate compound that transfers energy to the dye molecules. This energy transfer results in ground-state electrons being “kicked up” to a higher energy state called the excited state. The visible glow results as an excited-state dye molecule loses energy as visible light and returning back to the ground state.
In general, the speed of a chemical reaction increases as the temperature increases. (The speed of a reaction is also proportional to reactant concentration.) Typically, two reactants must collide with sufficient energy to overcome the activation energy barrier.
At a higher temperature, a larger fraction of the reacting molecules have sufficient energy to exceed the activation energy and thus react upon collision. Therefore, at a higher temperature, the glow is brighter because the number of molecules reacting is greater. Likewise, at a lower temperature, the lower intensity of the glow indicates the reaction speed is slower. Since each light stick contains a fixed amount of material, the lower the temperature, the longer the light stick will glow but with less intensity. If an activated light stick is stored in a freezer, the rate of reaction becomes so slow that there is very little, if any, perceptible glow. However, when removed from the freezer and warmed, the light stick will give off light, even after being stored for several months.

Light-sensitive paper forms images due to a photographic process called blueprint or cyanotype. Cyanotypes are made by mixing aqueous solutions of potassium ferricyanide and ferric ammonium citrate (green type). This mixture is then coated onto paper, textiles, or any other natural material and dried in the dark. Exposure to UV light (natural sunlight is the traditional light source, but UV lamps can also be used) causes the iron(III) (ferric) ions to reduce to iron(II) (ferrous) ions with citrate ion as the electron donor. The iron(II) ions then react with the ferricyanide ions to form insoluble Prussian blue, which is essentially ferric ferrocyanide [also called iron(III) hexacyanoferrate(II)]. After the above reaction sequence is completed, the print is washed in water to remove the soluble unexposed salts. Upon drying, the final image darkens as a result of slow oxidation in air.
The cyanotype process has remained virtually unchanged since its invention by Sir John Herschel (1792–1871) in 1842. Herschel was an astronomer, and he used cyanotype as a way of copying his intricate notes. He placed his notes over a sheet of blueprint paper and placed the paper in sunlight. Given a long enough exposure time, sunlight exposed the blueprint paper through the white areas of the page, thus creating a “photocopy.” Anna Atkins (1799–1871), a botanist, became the first person to photographically illustrate a book using cyanotypes. Atkins’ book, British Algae: Cyanotype Impressions, uses 424 cyanotypes. The blueprints used in engineering and architecture were originally cyanotypes.

UV-sensitive beads contain pigments that change color when exposed to UV light from the sun or other sources. When removed from UV exposure, they will turn back to their original white or colorless form. The lower-energy pigment molecules consist of two flat planes at right angles to each other. UV light energy causes the two planes to twist into one plane, which is the colored and higher energy form of the pigment. The higher-energy form loses energy in the form of heat, rather than light, to convert back into the lower-energy form.

Exposing UV beads that have been coated with different sun-protection products affects how quickly and deeply the beads change shade. Beads covered with no sun protection product or a low SPF product quickly change to a deep shade. Those covered with a high SPF product remain white or nearly white.

Placing different types of fabric over the UV beads shows that fabrics offer various degrees of UV protection. The density of the weave plays a more important role than the color or type of fabric. Several lines of UV-blocking clothing are commercially available, and UV-blocking laundry additives such as SunGuard™ can be used to treat clothing.
Most plastic sunglass lenses are treated with a coating or contain an additive to block UV light. Sunglasses with a higher UV rating block more UV than those with a lower rating or no specific rating, typically causing differences in how quickly and deeply beads change color. Glass absorbs all high-energy UV light and much low-energy UV light.

The shade created by a building or tree is less protective than clothing and sunglasses. Even in the shade, UV light reflected from the surroundings can reach the beads. If an object is illuminated by sunlight, either directly or indirectly, it is also receiving at least some UV radiation. Going deeper into natural shade will reduce but not eliminate UV exposure. People on beaches and boats often get a suntan or burn even if they are in the shade because of UV reflection off the sand and water.

The temperature of the UV beads also contributes to the intensity of the observed colors. On a hot summer day with high UV levels, the high UV level causes the beads to become colored. The hot day, however, causes the colored beads to thermally convert to white at a faster rate. On a cold winter day with high UV levels, the UV light causes the beads to become colored as expected; however, less thermal energy is available to the colored beads so they are slower to convert to the colorless form. The result is more intensely colored beads on a cold sunny day than on a hot sunny day. The UV conversion to colored and the thermal conversion to colorless are examples of a forward and reverse reaction in equilibrium.

References

Sarquis, M.; Hogue, L.; Hershberger, S.; Sarquis, J.; Williams, J. Chemistry with Charisma (volume 1); Terrific Science Press: Middletown, OH 2009

Sarquis, M.; Hogue, L.; Hershberger, S.; Sarquis, J.; Williams, J. Volume 2 Chemistry with Charisma; Terrific Science Press: Middletown, OH 2010