Curriculum Connection: Grade 11 University Chemistry (SCH3U), Solutions and Solubility unit
In developing countries, thousands of people – many of them children – die every year from drinking contaminated water. Many of these countries cannot afford to build water treatment plants. In North America, where safe water is generally available, we spend millions of dollars on bottled water, draining sources of fresh water, and challenging
• What are the economic costs of building, maintaining, and monitoring water-purification plants?
• What are the social and environmental costs if these plants are not properly maintained and monitored?
• How effective are municipal wastewater treatment processes at removing pharmaceuticals such as hormones and antibiotics from our drinking water?
• What public health concerns are associated with the consumption of water bottled in plastic containers?
Students were assigned an article to read for homework and were asked to generate questions and answers before coming to class the next day when the cooperative learning (CL) activity was to be implemented. The articles were posted on a class Wiki, in numerical order. Each student in class was assigned an article number that matched a posted article. Copies were not distributed to the students as they had access to the articles on the website. This was just one way I tried to model sustainability in the class. However, if you are using hard copies, you may wish to use different coloured papers for each article (see Teacher Notes later in this article).
The reading articles are listed below with an accompanying brief synopsis:
Real Water – with added electrons! (http://www.guardian.co.uk/science/blog/2011/apr/21/real-water-added-electrons)
• A company by the name of Real Water, makes dubious claims about the damaging effects of drinking water. This article urges readers to critically analyze online information.
• Some claims made by the company include the following:
• “many food and beverages….are devoid of electrons,” which is harmful to health. Tap water is “stripped of its electrons” as it passes through the distribution system, from pipes, filters and water systems. The company claims that tap water contains free radicals that ‘pull away life force from the cell.” The company claims to add free electrons to water and raise its pH to an alkaline level.
• Drinking water is mainly acidic which causes many diseases to flourish when, in fact, the acidity of tap water does not make it dangerous at all. Tap water is regulated for safety.
Tread lightly: Give up Bottled Water (http://www.guardian.co.uk/environment/2008/mar/21/water.pledges)
• This article looks at consumer perception of bottled water being superior to tap water, when in fact, it isn’t necessarily better.
• There is no supporting evidence to prove that mineral water has more health benefits than tap water.
• Bottled water has a substantially higher carbon footprint in comparison to that associated with tap water.
• PET-based plastic bottles are made from crude oil; manufacturing PET leads to CO2 emissions.
• Plastic water bottles enter landfills to create environmental problems.
Studies reveal that water tastes like water
• Consumers cannot typically tell the difference between bottled and tap water as they both taste the same, suggesting that consumers purchase bottled water for reasons other than for taste.
• Dasani is bottled tap water, no different from tap water.
Male bass with female features found in U.S.
• Largemouth and smallmouth bass fish had female egg cells inside their sexual organs – hence, were intersex. These fish do not reproduce as well as effeminized fish.
• This phenomenon is linked to endocrine-disrupting hormones (e.g., women’s birth control pills, estrogen in medicine) entering the river where these fish are found.
THREE-STEP INTERVIEW and JIGSAW Cooperative Learning Activity
1. Form same reading groups of two or three (join other students who have read the same article as you.) This is a homogenous reading group.
2. For three minutes, individually come up with as many questions about the article as possible. When prompted by the teacher, move on to the next step as outlined below.
3. Assign a role to each member of the reading group:
A. Interviewer – asks the questions
B. Interviewee – answers questions posed by the interviewer
C. Scribe – records pertinent details (suggested format: question followed by answer) onto recording sheet given by teacher
4. If you are a group of two, then one person is assigned roles A and C as described above, and one person is assigned role B.
5. When teacher signals end of the first three-step interview round, rotate roles clockwise so that interviewer (person A) is now the interviewee (person B) and the scribe (person C) is now the interviewer; i.e., A àB, BàC, CàA. The above process is repeated until the teacher signals the end of second round of three-step interview. When the teacher signals the end of the second round of three-step interview, roles again rotate clockwise so that each member performs a role he/she has not yet performed.
6. After three rounds, all scribed work is shared by all members of the same reading group so that every member has a record of the three rounds of interviews.
7. Return to your home or “placemat’ group that was formed originally. The home group comprises only one member from each reading group and so, can be referred to as a heterogeneous reading group. Assign a number to each member according to the reading article each person was expected to read for homework. For example, if you were assigned to read article number one, then you are individual number one. Thus, the heterogeneous reading group would be comprised of individuals one to four.
8. Individual number one summarizes his/her information based on article number one while individuals number two to four listen attentively and record the information in the appropriate section of handout entitled Reading Articles Summary Sheet. In other words, each person fills in summary sheet except for the person speaking. Continue the process (i.e., #2 now speaks and everyone listens/records etc.) until all members have shared and recorded their work.
9. At the end of the period, every student must submit the Reading Articles Summary Sheet handout (see below) to the teacher. Each student’s scribed work from the three-step interview must be added to the relevant portion of the table corresponding to your assigned reading article.
• Each reading article is identified by the coloured paper used to photocopy it if, in fact, you made hard copies, or is just recorded if read online. Each homogenous group receives one reading article and one instruction sheet detailing the 9 steps of the CL activity as shown above. The teacher reviews the instructions with the students (about 5 min.).
• Every student receives a Reading Articles Summary Sheet as shown below.
• It is up to the teacher’s discretion as to how much time to give for each round of the interview. Give limited time initially, then gauge students’ need for more time and adjust accordingly. Five minutes per round, for a total interview time of 15 minutes is suggested.
• The jigsaw activity should take 20 minutes – five minutes of sharing per reading article.
What Worked Well
Given the class size, some students had to work in pairs. Their modified roles (see step four above) worked out when they were informed of the fact that, in real life, a journalist typically asks questions and records the responses given by the interviewee. It was fitting to have one student take on a dual role, both as an interviewer and scribe. Such students did not know when to rotate roles as they were more efficient at conducting the interview. I told them to monitor their own activities and switch roles when it was appropriate to do so. They were told to go through a total of four rounds of the interview rather than the usual three rounds that students in groups of three had to go through.
Since the students had participated in a placemat activity the day before, they already knew the members of their home group (see step seven) and so, were able to quickly come together for the jigsaw activity. Of course, if such an activity did not precede this one, this activity can be adapted by giving each student a unique coloured reading article rather than
having it being shared amongst the homogenous group during the three-step interview. Alternatively, a list of students for each reading article can be posted around the classroom and students have to find their names. A reading list could also be posted online (class Wiki, class Moodle, etc.).
Ways to Improve Upon this Activity
I would give the assigned article (photocopied using a unique colour) as a hard copy to each student as it would likely improve the chances that they would read it and generate comprehensive questions/answers. They would then be asked to bring it to class, with the homework completed, as checked by the teacher. This would encourage students to actually
do the homework; I found, in general, that students did not come to class as prepared as they should have been. Having a coloured copy of the article would also make it easier for them to form homogenous reading groups for the three-step interview component. I found time was wasted in students looking for their same reading buddies. All they would have to do is locate classmates holding the same coloured article as they are. Ideally, as the activity is about sustainability, it would be beneficial to model the studies, by reading articles online only; however, I do believe the activity becomes somewhat easier for students if the hard-copies are used.
Another way to generate discussion would be to create a unique discussion forum for each reading article and expect students to make at least two posts (involving posing one question and answering a question posed by another student) prior to coming to class. This way, all members of a reading group would be held accountable for coming to class having posed a question and having answered someone else’s question. Utilization of the discussion forum could form part of a student’s assessment as learning.
The set of instructions may need to be reduced to fewer words so that students can quickly navigate through the steps without having to read extraneous words. The full-fledged instructions may be useful for the teacher to have while reading groups receive a truncated version of it.
A maraca was used to signal the end of a given round but an alternate signal could be used as I found the students were not paying attention to the sounds. I had to also turn the lights off.
Students spent more time on the three-step interview than initially planned for. Next time, students should be encouraged to scribe in point form rather than in full sentences. I noticed that students were copying some sentences directly from the article. The interviewee might consider paraphrasing his/her response for the benefit of the scribe. Of course, this would interrupt the interview that is intended to flow freely.
I had no time at the end of the class period to devote to whole class discussions which is something I definitely need to incorporate. Ideally, equal time should be allotted to the three-step interview, the jigsaw activity, and the whole class discussion. I would also like to have students complete an online survey (using Google forms) to get a sense of how the activity went for them in terms of what went well, what did not go well, how they could improve upon the activity, etc. This reflective piece may be counted towards a communication mark. Alternatively, students can complete an exit card that is aimed at allowing students to reflect quietly on the events of the class period. This adds an intrapersonal component to the lesson so that such students who learn best through this form of multiple intelligence are given an
opportunity to do so.
E1. analyze the origins and effects of water pollution, and a variety of economic, social, and environmental issues related to drinking water
E1.2 analyze economic, social, and environmental issues related to the distribution, purification, or use of drinking water (e.g., the impact on the environment of the use of bottled water) [AI, C]
Varsha Patel is a science teacher interested in co-operative learning. She is teaching at Georges Vanier Secondary School in the TDSB.