Stage 1 Desired Results s6

Amy Borg October 26th, 2007 UBD Lesson Jill Torres

Lesson Topic: ____Covalent Bonds_____ Grade level: __10-12____ Length of lesson: ___50 minutes___

Stage 1 – Desired Results Content Standard(s): 2.A. The student will be able to explain how atoms form compounds through bonding.

Understanding (s)/goals Essential Question(s): Students will understand:  Why do compounds form?  There are three types of bonds;  What is the basis of chemical covalent, ionic, and metallic. reactions?  Bonding creates compounds  How is bonding similar to other life  Bonding occurs because of the processes? octet rule  Bonding is essential for chemical reactions

Student objectives (outcomes): Students will be able to:  Identify what is required to make a covalent bond on the given worksheet from the lecture.  Identify the number of valence electrons for their assigned element from the periodic table, and record it.  Draw three examples of covalent bond using Lewis electron dot structures on the worksheet.  Demonstrate several examples of covalent bonding with a partner to satisfy the octet rule.  Analyze as a class the circumstances needed to form a covalent bond

Stage 2 – Assessment Evidence Performance Task(s): Other Evidence:  Construct an example of each type  Fill out worksheet on covalent of bond, with an explanation of bonds criteria for each type of bond. This  Partner with a classmate to form will be graded by a rubric. examples of covalent bonds  Exit slip: sketch three Lewis dot diagrams of covalent bonds on the worksheet

Stage 3 – Learning Plan Learning Activities: Materials:  Paper pigs  Tape  Note cards  Periodic table  Student worksheet  PP presentation Anticipatory Set: (10 min) Hook: “Pig Farm Analogy” To start off class I will use this analogy of covalent bonds and demonstrate it on the board:

In order to have a successful farm a farmer must have 8 pigs. If the farmer has more than 4 pigs, he tries to get more by either sharing pigs with another farmer (covalent) or buying pigs from another farmer (ionic). It a farmer has less then 4 pigs, he tries sell his remaining pigs to farmers who need them or he shares pigs.

I will ask the students: What do you think the pigs represent? The farm represents? What does the exchanging of pigs represent? Can you think of another analogy?

I will explain to the students that the pigs represent valence electrons, and how they exchange pigs represents bonding to form compounds.

Rationale: Bonding between atoms determines its reactivity. The basis of chemical reaction is breaking and forming of bonds. We will be investigating the many ways that atoms form compounds. The formation of compounds is essential to life. Certain atoms form certain bonds, and it depends on their properties and number of valence electrons. For example a covalent bond occurs when atoms share electrons to meet the octet rule. Atoms that take electrons from other atoms form ionic bonds because it creates an opposite charge on each atom that attract. Metallic bonds are created with an over abundance of electrons which makes them good conductors.

Body: (35 min) Instruction: (10 min) Students will have already learned what the octet rule is, and how to determine the number of valence electrons for an element based on is periodic table position. They have also learned how to draw Lewis electron dot diagrams. I will go through a brief description of what a covalent bond is, how they form, and what is required for them to form. Students will be filling out a worksheet simultaneously that coincides with my lecture:  Why do atoms bond?  How do atoms bond?  Sketch some examples from class

Activity: (25 min) 1. Students will be given a note card with an assigned an element on it. 2. Once students have their assigned element they will determine the number of valence electrons for the element and record it on the back of the card. 3. Students will move about the room to find another student they can form a covalent bond with to satisfy the octet rule. 4. Once everyone has found a bonding partner; I will record the different compounds on the board. a. The class will analyze why certain combinations are correct or incorrect. Students will get immediate feedback. 5. The students will find a different bonding partner. We will continue this pairing while time permits.

***It is important to makes sure all students are involved in the activity and understand the concept of covalent bonds***

Conclusion: (5 minutes) I will answer any questions students have about covalent bonds. Then I will show them another analogy of bonding at this website: http://ithacasciencezone.com/chemzone/lessons/03bonding/dogbonds.htm Ionic Bonds = One big greedy thief dog! Covalent Bonds = Dogs of equal strength. Metallic Bonds: Mellow dogs with plenty of bones to go around. I will collect their worksheets, so I can evaluate their understanding through sketches of bonding structures.

**This shows that our next lesson will be leading into different types of bonding. **