In this lesson students continue to learn about electrons and where they are located in terms of energy levels and orbitals. They do this through taking notes based on a Powerpoint, watching videos, and performing an activity.
In this lesson students perform an electron configuration activity. For this activity each student needs a set of bingo chips or other manipualtive. Some years I have used M&M's or Skittles as a treat to students as they perform the activity.
To begin the lesson I show students the first slide of the PowerPoint and have students answer a question at the top of their Notes Graphic Organizer. The question allows students to review what they already know concerning electrons by answering the following questions about Potassium (K)
1. How many valence electrons does it have?
2. Do a sketch of its atom (Bohr model) showing the electron shells.
By starting the lesson with this question it allows students to remember what they already learned about electrons. Then, I am able to tell students, "We are going to be learning more detail about where electrons are located."
Most students do well on this question. I get varied answers (which works well as an intro to this lesson) with regard to the number of electtons outer energy levels that some students put 9 electrons in the third energy level, while some put 8 electrons in the third and then 1 in the fourth. I use this as an opportunity to explain, "We will be learning about why we only put 8 in the third energy level, then start to put electrons into the fourth before going back to fill up the third today".
Also, because some students did not calculate neutrons correctly on the last quiz (see reflection on quiz unit 2 lesson 6) I make sure to stress how you need to round mass then subtract atomic number to determine number of neutrons.
This copy of a student's work shows the answers to the Engage question.
For the major part of the lesson students are taking notes, filling in an "Electron Configuration Tool", watching videos, and performing practice questions.
I begin the notes on slide 2 of the Powerpoint with a review of the Quantum Mechanical Model of the Atom and give an overall picture of electron configuration on slide 3.
I then go into the energy level on slide 4 and the sublevels on slides 5-8. As I teach the sublevels I show pictures of the sublevels as I describe the shapes.
On slides 9-11 I explain the Aufbau principle and have students make an "electron configuration tool" using a blank periodic table. The electron configuration tool helps students understand how to place the electrons in energy levels and sublevels. This is a picture of a completed "electron configuration tool"
Also as I explain the Aufbau Principle I have them watch a video to give them a visual of how electrons fill energy levels and orbitals.
On slides 12-17 I lead students through electron configuration practice as they fill them in on the first and second page of their notes.
On slide 13 I explain the Pauli Exclusion Principle and Hund's Rule which students then use as they learn about orbital box diagrams and perform examples on the third page of their notes.
Students then watch an Electron Configuration video to review what we discussed and visual box diagrams.
Finally I teach students about shorthand configuration on the last two slides of the PowerPoint (slides 22 and 23).
This is a copy of a student's filled in notes with the examples.
To help students review the information in the lesson I have them perform an electron configuration activity utilizing manipulatives (Bingo chips, skittles, or M&M's), an electron orbitals activity, and the electron configuration activity paper.
I have students begin by determining the total number of electrons for the atom and then take that number of the manipulative in their hand. They then place the manipulative into the orbitals on the electron orbital paper starting with 1s until they are all used. Finally students fill out the rest of the worksheet in terms of the electron configuration and box diagrams. See the reflection for a better understanding of how this works.
When I start this with students I go through the first example with them to make sure they understand how to use the manipulatives and electron orbital paper. This is a picture of how I have students place electrons for Beryllium in the manipulative and then fill out the electron configuration and box diagram.
This is a final picture of a student's work for the activity.
The last portion of this lesson involves students practicing what they learned by performing a homework paper. Students complete what they don't finish in class at home and then I stamp the paper for completion the next day. I go over the answers using the answer key.
The most common missed problems for electron configuration is students forgetting the f sublevels when they are doing electron configuration for elements past #57. Also, some students just get lazy and do not finish the last few full electron configurations. I make sure to stress to students how to use the tool to help in the beginning and to make sure to use the pattern with energy levels, sublevels, and then electrons to help.
With electron configuration I teach shorthand notation and box diagrams, but stress to students that they definitely need to understand the normal electron configuration and the others are extensions.