Bonding and Molecules and Alignment with the NGSS
HS-PS1-3-"Plan and conduct an investigation to gather evidence to compare the structure of substances at the bulk scale to infer the strength of electrical forces between particles."
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In this lesson, students will observe a phenomenon that directly correlates to the strength of an ionic bond. They will predict what will happen when certain variables are changed and then create an explanation to support their observations on what occurred during the experiment.
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Bonding and Molecules Introduction Lesson Plan
Start of Class:
To start the class, write the goals for the day up on the board. The goals for the day include:
1. Students will be able to describe ionic bonding as the sharing of electrons between 2 or more atoms
2. Students will be able to model how a molecule forms and how individual atom characteristics affects molecules
In addition, take attendance and pass back the students’ experiments they designed during day 2 of the lesson.
Introduction of Lesson:
To introduce the lesson, review the goals for the day with the students. Ask them what they think an ionic bond is to begin initiating their thinking about the laboratory activities for the day.
Lesson Instruction:
The lesson instruction for day 5 is adapted from the resource provided below:
Ionic Bonding Experiment Resource
The students will be performing a laboratory activity to help them investigate ionic bonding. A cotton string is soaked in a salt solution prior to class, the students then hang a pop tab with the string and ring stand. They burn the string and if they are gentle, the ashes of the string actually remain holding up the pop tab. Pass out the instructions to the demonstration that they will perform at the lab stations in their groups. On the paper, there will be a number 1-6. This is how the groups will be assigned.
Let the students sit in groups and first discuss the directions of the activity with the students as a whole class.
On a sheet of paper, have the students predict what will happen when they light the string on fire. At this point, it is my job to encourage some hypthoses and have the students think further if their hypothesis is not on point. Describe to them the variables that will be manipulated (i.e. the amount of time the string soaks in the salt solution, how long you let the string burn).Do not have the students share the hypotheses in front of the whole class; encourage them to work in groups during this part of the activity. Go around to each of the groups and listen to their hypotheses.
After the groups are finished sharing their thoughts, model what the students will be doing in the lab at the front of the room. This will help the students more accurately perform the experiment which will prevent hazards later on during the activity. The instructions for the activity will not only be written on the handouts the students receive, but also on the projector in front of the classroom. The instructions will include:
1. Gather all necessary materials
2. Follow safe laboratory measures all throughout the activity
3. Follow experiment instructions on setting up equipment (refrain from bending the string a lot)
4. Once your apparatus is set up, call me over to check it before proceeding
5. Follow through with the experiment – take observations before (hypothesis/prediction), during, and after demonstration
6. Make sure to explain what you did to test the results
Once I feel as though everyone is at a good point to continue, allow the students 5 minutes to get all of the necessary materials for the experiment. Instruct the students that after they feel they have set up the apparatus the correct way to call me over to check and make sure the groups can continue. Once students receive the “okay” from me, they can proceed with the lab. Make sure to challenge students’ thinking through their processing of the data. Ask questions like:
Make sure to walk around and check in with the groups and challenge their thinking to apply guided inquiry to the classroom. Once students have completed processing their data and taking all of the necessary observations, instruct them to clean up their lab area and move back to the seats. In the middle of the experiment, display questions up on the projector for students to answer. The lab area is separate from the desks so to account for some groups finishing earlier than others, direct the students to answer the questions they will see displayed via PowerPoint. The questions will include:
After all the papers are turned in, begin a discussion on different observations that were seen throughout the laboratory experiment. Ask for volunteers on their explanation of the phenomenon they exhibited. If the students do not come up with it themselves, have them inquire about the material that the string was soaked in. Tell the students that the string was soaked in a salt solution which is a form of an ionic bond. Then ask them how this type of bond could affect the ashes after the string was burned.
Project the definition of an ionic bond on the projector for the students: the sharing of electrons between two or more electrons. Relate this idea back to the very first day of the lesson and reinforce that atoms do not own their electrons, atoms can donate electrons to other atoms while other atoms crave electrons from another. Many students have the misconception that ions are produced from the addition of protons if the ion is positive, but now is the time to discredit that idea. In addition, collect the students’ responses from the questions they answered after they finished the activity. Let them know that they will be using their observations for their homework.
Assessments/Checks for Understanding:
Students will be required to turn in their questions that they answered after they completed the activity and were waiting for other groups to finish. Based off of these answers, I will be able to see what the students are thinking as well as how they are processing the concepts behind the experiment. Also, the students will be assessed in their conclusions that they turn in tomorrow. The purpose of this activity is to outline different parts of the scientific method while having them introduce themselves to ionic bonding. The students’ responses will indicate how well they understood the idea behind the lab that the ionc crystals were keeping the ashes together while the cotton string was burned.
Closure/Wrap-Up/Review:
Assign homework for the students that they must write up a conclusion to the experiment they performed in the lab similar to the explanation they wrote in class. Advise students that if they need to make revisions based upon the discussion that took place in class, they should do so. They must explain what is happening on a molecular level and support their ideas with observations they wrote down during the activity. Since they will be making revisions on their previous explanation, instruct them to write down how their explanation was incorrect by providing evidence.
The assignment is due typed up tomorrow in class. They must include formal definitions of important terms used throughout the activity. There will be directions to the assignment on the course website that students will be able to reference while completing the assignment. Essentially, explain that they must write the conclusion as if someone who had not taken this class before could understand and comprehend what is going on. That means they must define all scientific terms that were learned in this unit thus far.
To start the class, write the goals for the day up on the board. The goals for the day include:
1. Students will be able to describe ionic bonding as the sharing of electrons between 2 or more atoms
2. Students will be able to model how a molecule forms and how individual atom characteristics affects molecules
In addition, take attendance and pass back the students’ experiments they designed during day 2 of the lesson.
Introduction of Lesson:
To introduce the lesson, review the goals for the day with the students. Ask them what they think an ionic bond is to begin initiating their thinking about the laboratory activities for the day.
Lesson Instruction:
The lesson instruction for day 5 is adapted from the resource provided below:
Ionic Bonding Experiment Resource
The students will be performing a laboratory activity to help them investigate ionic bonding. A cotton string is soaked in a salt solution prior to class, the students then hang a pop tab with the string and ring stand. They burn the string and if they are gentle, the ashes of the string actually remain holding up the pop tab. Pass out the instructions to the demonstration that they will perform at the lab stations in their groups. On the paper, there will be a number 1-6. This is how the groups will be assigned.
Let the students sit in groups and first discuss the directions of the activity with the students as a whole class.
On a sheet of paper, have the students predict what will happen when they light the string on fire. At this point, it is my job to encourage some hypthoses and have the students think further if their hypothesis is not on point. Describe to them the variables that will be manipulated (i.e. the amount of time the string soaks in the salt solution, how long you let the string burn).Do not have the students share the hypotheses in front of the whole class; encourage them to work in groups during this part of the activity. Go around to each of the groups and listen to their hypotheses.
After the groups are finished sharing their thoughts, model what the students will be doing in the lab at the front of the room. This will help the students more accurately perform the experiment which will prevent hazards later on during the activity. The instructions for the activity will not only be written on the handouts the students receive, but also on the projector in front of the classroom. The instructions will include:
1. Gather all necessary materials
2. Follow safe laboratory measures all throughout the activity
3. Follow experiment instructions on setting up equipment (refrain from bending the string a lot)
4. Once your apparatus is set up, call me over to check it before proceeding
5. Follow through with the experiment – take observations before (hypothesis/prediction), during, and after demonstration
6. Make sure to explain what you did to test the results
Once I feel as though everyone is at a good point to continue, allow the students 5 minutes to get all of the necessary materials for the experiment. Instruct the students that after they feel they have set up the apparatus the correct way to call me over to check and make sure the groups can continue. Once students receive the “okay” from me, they can proceed with the lab. Make sure to challenge students’ thinking through their processing of the data. Ask questions like:
- Why is the pop tab still hanging from the ashes?
- What is happening to the ashes to make them hold up the pop tab?
- If the pop tab fell, what changed between your experiment and others to cause this change?
- What is happening on a molecular level to the string/ashes to cause this phenomena?
- What parts of an atom are holding the string’s ashes together? (This connects to the previous day’s lesson.)
- What kind of molecule was the string soaked in? If the string was not soaked in the salt, would the ashes still hold together?
Make sure to walk around and check in with the groups and challenge their thinking to apply guided inquiry to the classroom. Once students have completed processing their data and taking all of the necessary observations, instruct them to clean up their lab area and move back to the seats. In the middle of the experiment, display questions up on the projector for students to answer. The lab area is separate from the desks so to account for some groups finishing earlier than others, direct the students to answer the questions they will see displayed via PowerPoint. The questions will include:
- What was your hypothesis prior to the activity? After seeing what happened, would you change your hypothesis? If so, what caused you to change it?
- What do you think caused the pop tab to stay hanging from the ashes?
- How might the molecular structure of the string affect the observations you saw?
- How might this relate to ionic bonding?
After all the papers are turned in, begin a discussion on different observations that were seen throughout the laboratory experiment. Ask for volunteers on their explanation of the phenomenon they exhibited. If the students do not come up with it themselves, have them inquire about the material that the string was soaked in. Tell the students that the string was soaked in a salt solution which is a form of an ionic bond. Then ask them how this type of bond could affect the ashes after the string was burned.
Project the definition of an ionic bond on the projector for the students: the sharing of electrons between two or more electrons. Relate this idea back to the very first day of the lesson and reinforce that atoms do not own their electrons, atoms can donate electrons to other atoms while other atoms crave electrons from another. Many students have the misconception that ions are produced from the addition of protons if the ion is positive, but now is the time to discredit that idea. In addition, collect the students’ responses from the questions they answered after they finished the activity. Let them know that they will be using their observations for their homework.
Assessments/Checks for Understanding:
Students will be required to turn in their questions that they answered after they completed the activity and were waiting for other groups to finish. Based off of these answers, I will be able to see what the students are thinking as well as how they are processing the concepts behind the experiment. Also, the students will be assessed in their conclusions that they turn in tomorrow. The purpose of this activity is to outline different parts of the scientific method while having them introduce themselves to ionic bonding. The students’ responses will indicate how well they understood the idea behind the lab that the ionc crystals were keeping the ashes together while the cotton string was burned.
Closure/Wrap-Up/Review:
Assign homework for the students that they must write up a conclusion to the experiment they performed in the lab similar to the explanation they wrote in class. Advise students that if they need to make revisions based upon the discussion that took place in class, they should do so. They must explain what is happening on a molecular level and support their ideas with observations they wrote down during the activity. Since they will be making revisions on their previous explanation, instruct them to write down how their explanation was incorrect by providing evidence.
The assignment is due typed up tomorrow in class. They must include formal definitions of important terms used throughout the activity. There will be directions to the assignment on the course website that students will be able to reference while completing the assignment. Essentially, explain that they must write the conclusion as if someone who had not taken this class before could understand and comprehend what is going on. That means they must define all scientific terms that were learned in this unit thus far.