Why can’t we drink the water from some of the drinking fountains at school?
Introduction to chemical reactions
8th grade Integrated Science
Eric DeJulio
EDTEP 587
Subject area description:
This topic unit will be taught to students in 8th grade integrated science. The school has a science honors program in place, so this unit will be taught to both honors students and students in the mainstream integrated science classes. As the school is a suburban middle school, the student base in not overly diverse those observed in urban school districts (the school is 73% Caucasian). A small percentage of students (~3.5%) will be English language learners.
This unit will be taught at the beginning of the school year and serves as their first middle school introduction to chemistry. Little/no prerequisite knowledge is necessary. This unit will feature a lot of inquiry scaffolding, so no prerequisite skills relating to inquiry would be required for this unit. However, it would be helpful if students had some basic inquiry-related skills from the previous school year, including skills relating to observation, experimental design, and data analysis. The teacher recognizes that students will have varying experiences with inquiry, so all of these steps will be taught, reviewed, and modeled in class. The unit on chemical reactions will not finish with this inquiry but will continue through other introductory chemistry topics, such as the periodic table and the structure of an atom. Future topics will include weather, genetics, earth science, and evolution.
Essential questions:
Why can’t we drink water from some of the water fountains at school? Why is water containing lead bad for me to drink? Since lead is a metal, why don’t I see chunks of lead in contaminated water? How do we test for lead in the water, especially since I can’t see it?
These questions are relevant to students’ lives, especially since the school is in the process of testing/fixing contaminated water sources in the school. (There are “Water is NOT ok to drink” signs up around school) Since students see this everyday at school, it should lead to an intriguing investigation into the school’s water supply, which will continue throughout the remainder of the unit to include the chemistry behind the water tests. In order to help make this topic personally relevant to students, students will start by learning about the biological impacts of lead ingestion. To really investigate why the lead is in the water supply, students need to understand the how chemical reactions change lead from a metal into a solution that can contaminate water. To understand how this happens at their school, they will also need to examine how different conditions affect the leaching of lead into water, such as temperature and pH.
Learning goals and objectives:
- Students will develop abilities necessary to do scientific inquiry. (EALR 2.1)
- Students will identify manipulated and responding variables in an experimental set-up.
- Students will generate questions that can be answered through scientific investigation (benchmark 2.1.1).
- Students will design and conduct scientific investigations (benchmark 2.1.2).
- Students will interpret scientific results and make conclusions based on evidence and inferential logic (benchmark 2.1.3).
- Students will create and analyze models to illustrate the behavior of objects, events, systems, and processes (benchmark 2.1.4).
- Students will apply their understanding of atoms to explore chemical reactions.
- Students will understand and justify that atoms can combine in various ways into molecules which may change their physical properties (Atlas AM), and that these changes may alter the biological effect of the chemical.
- Students will verify the factors that influence chemical reactions (temperature, acidity, etc.) (Atlas CR).
- Students will gain a deeper understanding of atoms.
- Students will know that all matter is made up of atoms (Atlas CR).
- Students will predict and support their predictions of chemical reactions.
- Students will understand endothermic and exothermic reactions.
- Students will understand and describe physical and chemical changes (benchmark 1.3.3).
- Students will learn to effectively communicate scientific understanding to others (EALR benchmark 2.1.5).
- Students will illustrate conclusions using visual representations.
- Students will present findings and conclusions to the class.
- Students will organize evidence so that others can understand their conclusions.
- Students will learn that effective group collaboration is integral to scientific investigation.
- Students will listen to other group members’ ideas and concerns.
- Students will actively participate in group activities.
- Students will analyze the advantages and disadvantages of doing inquiry in a group.
Unit matrix
As students will be working in groups each day, 2 objectives will be part of each day’s lesson. They are listed below.
5.1 Students will listen to other group members’ ideas and concerns.
5.2 Students will actively participate in group activities.
These objectives will be assessed through informal teacher observation and peer and self assessment.
WEEK 1, DAY 1: (50 minutes) Introduction the biological effects of heavy metals
1. What students are doing / Warm up – Why can’t we drink the water from some of the drinking fountains at school? (show a picture of a sign above a drinking fountain)Students, in small groups, will analyze different short articles related to heavy metal poisoning (fall of Rome, lead poisoning in low SES urban areas, mercury toxicity and fish, etc.)
Students will then teach each other about their article (structured by questions on a worksheet). – Worksheet will inquire:
- These are all metals. How do they get inside our bodies to make us sick?
- In what form are they when they make us sick? How did they get in that form? (for example, are they small pieces of metal, dissolved in a liquid, mixed with other things that make us sick, etc.)
- Do you think we’d get sick if we ate the metal in any form? In other words, would you expect me to get sick if I swallowed a chunk of one of the metals?
2. Objectives (no more than two, numbered for example as 1.2, 3.1, etc. from list on previous page ) / 2.1 Students will understand and justify that atoms can combine in various ways into molecules, which may change their physical properties (Atlas AM) and understand that these changes may alter the biological effect of the chemical.
3. Reasons for content and instructional strategy / This is the beginning of the unit. This lesson is solely meant to give the students a context for why it is important to care about heavy metal poisoning – it has biological consequences. We will not be going into much depth at this stage, as it is not a unit focused on biology, but we will revisit the biological implications of heavy metal poisoning when we make our final model. This lesson incorporates eliciting students’ ideas, as I want to learn what they know/how they talk about this topic. Also, allowing students to teach each other takes the whole process closer to their comfort zone by taking out the academic talk that would result if I tried to teach this.
4. Evidence of understanding / Informal observation of student lessons
5. Cultural Responsiveness / Students will be encouraged to construct and share their own understanding of heavy metal poisoning based upon their understanding of the short article. Students will teach each other, which naturally incorporates their knowledge/language into the lesson; this makes the content more accessible to the students in the class. During group activity, students are encouraged to work together within groups and as a class rather than compete. Teacher will monitor student interaction in groups to ensure all students are participating and all ideas are honored. Teacher will model the importance of honoring student ideas by re-voicing them so that other students' can hear and add to them.
6. Resources / Butcher paper, markers
WEEK 1, DAY 2/3: (100 minutes) Basic atomic structure, states of matter, and physical/chemical changes (structure inquiry)
1. What students are doing / Warm up – Teacher will put a 2 items in front of the class. Students will answer the following questions:- What are makes up these items?
- Why are they different?
Students will engage in interactive concept building to get to the point that all matter is made up of atoms and atoms have both + and – charges associated with them (relate to magnetism that they studied in 7th grade). Students will review the nomenclature of atoms (nothing to do with organization, trends, etc. at this time) and states of matter (draw examples of the different states in groups of 4 and present to class). Students will do a lab activity regarding chemical and physical changes:
http://wow.osu.edu/Chemistry/cpchanges.htm
This activity will be altered to include endothermic and exothermic reactions.
This will then be related back to the metal leaching scenario by having the students first respond to the following questions, share with a neighbor, and then discuss as a class:
- If heavy metals are in the water, what state of matter are they in?
- If you think it’s a solid, how could we prove this? Is this a physical or chemical change? How do you know?
- If you think it’s a liquid, how could we prove this? Is this a physical or chemical change? How do you know?
2. Objectives (no more than two, numbered for example as 1.2, 3.1, etc. from list on previous page ) / 3.1 Students will know that all matter is made up of atoms (Atlas CR)
3.4 Students will understand endothermic and exothermic reactions.
3.5 Students will understand physical and chemical change.
3. Reasons for content and instructional strategy / Phase 1 of Inquiry: Building a Knowledge Base. Students need to have quite a bit of background information before they are even able to generate questions and hypotheses for the inquiry. I will elicit students’ ideas regarding atoms during the warm up. This will then be used to transition into the interactive concept-building portion of the lesson, which will be used to teach/review the basic information relating to the composition and states of matter. Students will then do a hands-on activity to investigate chemical and physical reactions. I want students to actually feel, see, and hear the different types of changes that take place in reactions; hopefully, this will help students retain the information, as it allows them to experience the reaction.
4. Evidence of understanding / I will informally assess student understanding during the warm up debrief. Journal entries will be checked for understanding of the lab activity. The ability of students to transfer information from the lab into another situation will be assessed through class discussion about metal leaching and journal entries.
5. Cultural Responsiveness / Students will be encouraged to construct and share their own understanding of basic atomic structure, states of matter, and physical/chemical changes based upon their own observations of the lab and their previous life experiences. During group activity, students are encouraged to work together within groups and as a class rather than compete. Teacher will monitor student interaction in groups to ensure all students are participating and all ideas are honored. Teacher will model the importance of honoring student ideas by re-voicing them so that other students' can hear and add to them.
6. Resources / Butcher paper, markers, supplies for lab activity, SAFETY: chemicals
WEEK 1, DAY 4/5: (100 minutes) Factors that influence chemical reactions, introduction of culminating activity
1. What students are doing / Warm up: Students will address the following questions:- When you eat hard candy and allow it to dissolve in your mouth, is it a physical or chemical reaction? Explain your reasoning. (This is tricky!)
- What is a reaction?
- What causes reactions?
- What factors can affect reactions?
Students will be introduced to the culminating assessment. Students will begin to prepare KWL charts regarding the content of the inquiry.
2. Objectives (no more than two, numbered for example as 1.2, 3.1, etc. from list on previous page ) / 2.2 Students will verify the factors that influence chemical reactions (temperature, acidity, etc.) (Atlas CR).
1.2 Students will generate questions that can be answered through scientific investigation (benchmark 2.1.1).
3. Reasons for content and instructional strategy / Before students can begin to generate reasonable questions on which to begin an inquiry, they must have a background in the factors that influence chemical reactions. The teacher will model the experimental design thought process to students through a cognitive apprenticeship approach. I have planned to do this as an in-class structured inquiry so that they get hands on experience in seeing the results when they alter different experimental conditions. This knowledge is necessary for students to be able to hypothesize how metal is able to leach into the water supply. In this class period, students will begin to brainstorm different questions related to the culminating inquiry project. I will heavily structure the question development portion of this activity, as I don’t believe that many of these students will have much experience with developing their own questions. This process will be continued in the next class period.
4. Evidence of understanding / Student journals will be checked for understanding. Teacher will review KWL charts.
5. Cultural Responsiveness / Students will be encouraged to construct and share their own understanding of chemical reactions and suggest propose factors that may influence these chemical reactions. Teacher will allow students to incorporate these ideas into the lab activity, if the materials are accessible. This will model that students have good ideas that should get scientific merit and should help increase motivation by giving students ownership in the activity. During group activity, students are encouraged to work together within groups and as a class rather than compete. Teacher will monitor student interaction in groups to ensure all students are participating and all ideas are honored. Teacher will model the importance of honoring student ideas by re-voicing them so that other students' can hear and add to them.
6. Resources / Materials for chemical reactions lab
WEEK 2, DAY 1: (50 minutes) What makes a good scientific question, developing questions for inquiry
1. What students are doing / Warm up: “What makes a good scientific question?”Students will debrief the warm up as a class and make rules about creating scientific questions.
Students will be introduced to the model that we will use for the experiment – something like Metals ???????? leaches into water health implications
Students will think/pair/share about conditions that they think could influence metal leaching into water. Students will then brainstorm questions relating to these experimental conditions and will analyze questions regarding the rules that were created at the beginning of class, and they will choose the manipulated variable that they will investigate in their inquiry.
2. Objectives (no more than two, numbered for example as 1.2, 3.1, etc. from list on previous page ) / 1.1 Students will identify manipulated and responding variables in an experimental set-up.
1.2 Students will generate questions that can be answered through scientific investigation (benchmark 2.1.1).
1.5 Students will create and analyze models to illustrate the behavior of objects, events, systems, and processes (benchmark 2.1.4).
3. Reasons for content and instructional strategy / In order to do an inquiry, students need to understand how to develop good scientific questions. We will do this by allowing the students to come up with their own rules about what they think makes a good scientific question, and then these rules will be discussed as a class in comparison to what rules scientists actually use. We will then continue to apply this to our own inquiry. I will give them a very basic model that will be used to develop their inquiry question; I am giving them a model, as I don’t think that they will have the background knowledge required to develop their own model. However, they can use this to create their own question, allowing them some ownership in the process. They will do this in their inquiry groups, which begin to build the community that is necessary for the students to do inquiry.
4. Evidence of understanding / Teacher will monitor rules that students develop to assess overall understanding of scientific questioning. Teacher will also monitor proposed inquiry questions to assess students’ internalization and application of scientific questions rules.
5. Cultural Responsiveness / Students will be encouraged to brainstorm variables that could be related to the leaching of heavy metals into water. Teacher will allow students to incorporate these ideas into the lab activity, if the materials are accessible. This will model that students have good ideas that should get scientific merit and should help increase motivation by giving students ownership in the activity. Also, students who are slow to speak or uncomfortable with speaking in class are given time through a think/pair/share model of group discussion. During group activity, students are encouraged to work together within groups and as a class rather than compete. Teacher will monitor student interaction in groups to ensure all students are participating and all ideas are honored. Teacher will model the importance of honoring student ideas by re-voicing them so that other students' can hear and add to them.
6. Resources / none
WEEK 2, DAY 2/3: (100 minutes) Background knowledge for creating hypotheses, justifying the hypothesis