
Lesson Plan Template:
General Lesson Plan

Learning Objectives: What should students know and be able to do as a result of this lesson?
 Students will be able to determine the number and arrangement by energy level of electrons in an element.
 Students will be able to construct Electron Dot Diagrams (Lewis Structure).
 Students will be able to conclude that elements in the same group have the same number of valence electrons.
 Students will recognize patterns in the arrangement of the periodic table.

Prior Knowledge: What prior knowledge should students have for this lesson?
 Students will need to know how to figure out the number and arrangement of electrons in an atom. They need to be familiar with the Bohr model of an atom. They need to know that the first energy level of an atom is complete with 2 electrons, the second energy level is full with 8, the third energy level can hold up to 18, etc.
 Students need to know the definition of a period and a group on the periodic table.

Guiding Questions: What are the guiding questions for this lesson?
What patterns exist within families or groups on the periodic table?

Teaching Phase: How will the teacher present the concept or skill to students?
Script:
"Valence electrons are the electrons in the last energy level of an atom. It's these electrons that determine an element's chemical properties and how it bonds or doesn't bond with other atoms. An Electron Dot Diagram (also called Lewis Structure) is a model that shows only the "important" valence electrons. Let's draw a couple examples together..."
Teacher will model how to draw an electron dot diagram for Magnesium.
While modeling how to draw an Electron Dot Diagram for Magnesium, the teacher will prompt the class with the following questions:
 How many electrons does Magnesium have? (Ans: 12)
 We know that Magnesium has 12 total electrons, how many fit in the first energy level? (Ans: 2)
 How many will fill up the second energy level? (Ans: 8)
 Do we need a third energy level? (Ans: yes)
 How many should I put in the third energy level? (Ans: 2)
Teacher may want to draw a Bohr model of Magnesium and then use it to draw the Electron Dot Diagram for Magnesium.
How many electrons are in the last energy level of Magnesium? (Ans: 2) These are its valence electrons. These are the only electrons we account for while drawing an Electron Dot Diagram.
Electron Dot Diagram for Magnesium:
Teacher will use the same questioning strategy to model how to draw the Electron Dot Diagram for Neon.
Electron Dot Diagram for Neon:

Guided Practice: What activities or exercises will the students complete with teacher guidance?
Students will draw Electron Dot Diagrams on the "Electron Dot Diagram Periodic Table" worksheet.
Students will use a periodic table to figure out the number of valence electrons for the first 18 elements and construct the corresponding dot diagrams.
Teacher will monitor student progress, checking for understanding and any errors. Teacher may instruct students to draw the Bohr model first.
Teacher will probe students with the following questions:
 How many electrons does your element have?
 How do we figure out the number of electrons?
 How many electrons are in the first energy level?
 How many electrons fill up the second energy level, etc.?
(Ans: the number of electrons are the same as the number of protons; the atomic number tells us the number of protons; The first energy level can hold up to 2 electrons, the second up to 8, the third up to 18, etc.)

Independent Practice: What activities or exercises will students complete to reinforce the concepts and skills developed in the lesson?
Students will use the periodic table they created with the Electron Dot Diagrams to answer the followup questions. The followup questions are on "Electron Dot Diagram Periodic Table" worksheet.

Closure: How will the teacher assist students in organizing the knowledge gained in the lesson?
Teacher facilitates a quick discussion on the followup questions. See the Answer Key  Electron Dot Diagram Periodic Table.
Teacher could use the following closure as a quick class conversation or as an exit slip. Students should have a Periodic Table available.
Script:
"Valence electrons determine how an element reacts, its properties, and how it bonds with other atoms".
 What element(s) do you think may have similar chemical properties to Potassium? (Suggested Ans: Any elements in Group 1 on the periodic table. Eg.: Hydrogen, Lithium, Sodium, Rubidium, Cesium, etc.)
 What element(s) do you think will react like Radon? (Suggested Ans: Any elements in Group 18 because they have the same number of valence electrons. Eg.: Helium, Neon, Argon, Krypton, etc.)
 What element(s) might bond like Oxygen does? (Suggested Ans: any element in the same group as Oxygen (group 16) because they have the same number of electrons in the last energy level. E.g.: Sulfur, Selenium, etc.)
 Show the following video to conclude and apply what they have learned: http://youtu.be/ulyopnxjAZ8
 Students should give examples of how elements in the same group have similar properties after completing the Dot Diagrams and watching the video.

Summative Assessment
Lab worksheet:
Suggested grading: Students earn up to 39 points
See the Answer Key for "Electron Dot Diagram Periodic Table"
 Were the Electron Dot Diagrams drawn correctly on the periodic table?
 Did students recognize the patterns of valence electron arrangement?

Formative Assessment
While modeling how to draw an Electron Dot Diagram (Lewis Structure), the teacher will prompt the class with the following questions:
 How do I figure out the number of electrons? How many electrons fill up the first energy level, the second, etc.
 What is a valence electron?
The teacher will also monitor and check the dot diagrams as student complete the lab worksheet. She will assist as needed.

Feedback to Students
The teacher will monitor students' progress as they complete their periodic table with electron dot diagrams. The teacher will assist and prompt students as needed.
The teacher can prompt with the following questions:
 How many electrons does your element have?
 How do we figure out the number of electrons?
 How many electrons are in the first energy level?
 How many electrons fill up the second energy level, etc.?
(Ans: the number of electrons are the same as the number of protons; the atomic number tells us the number of protons; The first energy level can hold up to 2 electrons, the second up to 8, the third up to 18, etc.)
Students will have the opportunity to fix any errors as they are creating their electron dot diagram periodic table.