Key ideas

The electrons surrounding an atom are situated in regions around the nucleus called “energy levels”. An energy level to represent the 3-dimensional space surrounding the nucleus wherein electrons space most likely to be. The an initial energy level is closest to the nucleus. The second energy level is a little farther away than the first. The 3rd is a little farther away than the second, and so on.Each power level deserve to accommodate or “hold” a different number of electrons before extr electrons start to go into the following level. When the very first energy level has actually 2 electrons, the next electrons get in the second energy level until the second level has 8 electrons. As soon as the second energy level has 8 electrons, the following electrons enter the 3rd energy level until the third level has actually 8 electrons.When the 3rd energy level has 8 electrons, the following 2 electrons enter the fourth power level.The electron in the power level farthest from the nucleus are called valence electrons.Atoms in the same shaft (group) in the periodic table have actually the same variety of valence electrons.


Students will certainly again focus on the an initial 20 elements. Student will an initial look in ~ a diagram and animation to know the simple pattern of the arrangement of electrons on energy levels roughly an atom. Students will be offered cards with information about the electrons and also energy levels because that each that the an initial 20 atoms. They will certainly again try to correctly complement the cards with each element.

You are watching: Electrons in the outermost principal energy level


Students will have the ability to interpret the information provided in the routine table to explain the setup of electrons on the power levels about an atom.


Download the student task sheet, and distribute one per student as soon as specified in the activity. The task sheet will serve together the “Evaluate” ingredient of each 5-E great plan.

About this Lesson

Be certain that the 20 atom surname cards room posted roughly the room. Friend will require the 5 cards ~ above the best hand next of every sheet. This lesson is intended together a follow-up to thing 4, class 2.

For lesson 4.3, students have the right to play the routine Table Game, game #2. This is an online variation of the routine table card video game from this lesson that you have the right to assign as course work or homework ~ students have played the game in the classroom.

Have groups work together to ar each card with its correct atom.

See more: 7 Tips On How To Convince Your Parents To Get You A Dog, How To Convince Your Parents To Let You Get A Dog

Show students that you have 80 cards (4 because that each that the an initial 20 elements). Prior to distributing the cards, define that each card consists of information about electrons and energy levels because that the first 20 facets of the routine table. The students’ project is to check out the map carefully, number out which element the card is describing, and put the card at the spot in the room for that element. Repeat students the they will should count the electron in bespeak to determine each atom. When students recognize what their assignment is, distribute the cards come groups.


Have students look for fads in rows and also columns the the an initial 20 elements in the regular table.

Continue to job the photo Periodic table of energy levels for facets 1–20 and have students look in ~ their task sheets to find patterns in the variety of electrons within each power level.

Have students look in ~ the durations (rows going across).

Number of power levels in each period

The atom in the very first period have actually electrons in 1 energy level.The atoms in the second duration have electrons in 2 energy levels.The atom in the third duration have electron in 3 energy levels.The atom in the fourth duration have electrons in 4 energy levels.

How the electrons fill in the energy levels

First power level = 1, 2Second energy level = 1, 2, 3, …8Third power level = 1, 2, 3, …8