Day 1 of 3--Student Inquiry Regarding Endothermic and Exothermic Reactions: Designing an Investigation

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Objective

SWBAT design an investigation that allows them to collect data in order to answer a specific question regarding endothermic and exothermic reactions.

Big Idea

Differing concentrations of reactants may (or may not) have measurable effect on heat flow; investigation procedures can be developed in order to collect data that seeks to find answers to specific questions.

Why This Lesson?

In this lesson, students will apply what they know and have observed about endothermic and exothermic reactions to choose a question from a provided list OR develop their own question that they would like to seek the answer to.  Through this process, students are engaged in SEP 3 - Planning and Carrying Out Investigations and SEP 1 - Asking Questions.

Today is Day 1 of a 3-day lesson series.  The subsequent lessons can be found here: Day 2 and Day 3.

Through their investigation, students will be working on developing their understanding of Crosscutting Concept XC-EM-HS-2: Changes of energy and matter in a system can be described in terms of energy and matter flows into, out of, and within that system.  Students are also building their ability to meet Performance Expectation HS-PS3-1: Create a computational model to calculate the change in the energy of one component in a system when the change in energy of the other component(s) and energy flows in and out of the system are known. 

Warm-Up

5 minutes

While I take attendance, students do a warm-up activity in their composition Warm-Up/Reflection books.  I use warm-ups to either probe for students' prior knowledge about the day's upcoming lesson or to have them bring to mind and review what they should have learned previously.  (To read more about Warm Up and Reflection Books, please see the attached resource.) 

Today's Warm-Up: "What makes a 'good' scientific investigation?"

In this case, the warm-up is asking students to recall previous learning throughout their science experiences that a good scientific investigation seeks to answer a question, has repeatable and objective steps to follow, and allows for a collection of data.  It is also preparing students to design their own investigations.

If time permits, I walk around with a self-inking stamp to stamp the completed warm-ups indicating participation, but not necessarily accuracy.  On days when there is too much business keeping, I do not stamp.  Students have been told that warm-ups are occasionally immediately checked and other times not.  At the end of each unit, Warm-Up/Reflection Books are collected and spot-checked.  

Whole Class Instruction: How to Design Investigations

15 minutes

I begin by asking my class to share some of their answers to the Warm-Up question.  I record some of their ideas on the board.  If students are not hitting key points I am looking for, I will ask probing questions to spark the discussion in the direction I want.

Key points I am looking to hear:

  • Step-by-step procedure that is replicable
  • Clear details included in procedure, such as measurements 
  • Recordable data
  • Quantitative data
  • Uses available materials
  • Seeks to answer a specific question

After students offer their answers and we discuss how these characteristics contribute to a "good" investigation, I offer students a plan for today's working time.

Students are directed to work in groups of 2-4 students.  I have found that 3 is an ideal number most of the time, but I do allow enthusiastic pairs or the occasional quartet to work together.  By this time in the year, students are more aware of which peers will pull their weight in a group and which will not. Allowing them to self-select means that students will need to deal with the repercussions of those decisions.  Most will choose wisely.  I allow students to move seats so that they are sitting with their investigation group.

Then, I handout Chemistry - Designing an Investigation Endothermic/Exothermic, one to each student (although it could be handed out one per group).

Scaffolded Investigation Planning

35 minutes

I give student the rest of the class period to work on their investigation development.  They will need to figure out and document a proposed procedure to follow, and develop data tables that they can use for data collection.  

Because I want the entire investigation to be student-designed, I am careful not to offer too much help.  That can be really difficult, but here I am much more concerned about the process of designing an investigation and not the end results.  In fact, as I walk around and check-in with students, I can see there are several investigation designs that will not yield useful results.  Although it is really difficult, I hold back on intervening too much because I want students to discover that their investigation doesn't yield useful results on their own.  This will make a much more lasting impact than if I correct them at the outset.

Checking In

5 minutes

For the last five minutes of class, I direct my students' attention to the front and just briefly check-in with each group to gauge how far along in the design process they are.  My goal is for students to have a viable procedure to follow the next class period.  Groups that are running behind are directed to get together and finish a procedure development during lunch in my room.