Atomic numbers 5 through 10 are in the first row of the p block, and the p sublevels start on the second energy level. Therefore, the 5th through 10th electrons go into the 2p sublevel. Atomic numbers 11 and 12 are in the third row of the s block, so the 11th and 12th electrons go into the 3s sublevel. Because atomic numbers 13 through 18 are in the p block, we know they go into a p sublevel.
Because the p sublevels begin on the second principal energy level and atomic numbers 13 through l8 are in the second row of the p block, the 13th through 18th electrons must go into the 3p sublevel. The position of atomic numbers 19 and 20 in the fourth row of the s block and the position of atomic numbers 21 through 30 in the first row of the d block show that the 4s sublevel fills before the 3d sublevel.
Moving through the periodic table in this fashion produces the following order of sublevels up through 6s:. Notice that atomic numbers 57 through 70 on the periodic table below are in the 4f portion of the table. It is a common mistake to forget that the 4f sublevel is filled after the 6s sublevel and before the 5d sublevel.
Therefore, nickel can be found in the fourth period of the periodic table. Based on electron configurations, the periodic table can be divided into blocks denoting which sublevel is in the process of being filled.
The s , p , d , and f blocks are illustrated below. The figure also illustrates how the d sublevel is always one principal level behind the period in which that sublevel occurs.
In other words, the 3 d sublevel fills during the fourth period. The f sublevel is always two levels behind. The 4 f sublevel belongs to the sixth period. Skip to main content. The Periodic Table. Search for:. Determine the block each element belongs in by its electron configuration. What makes these music notes unique? Summary The horizontal rows of the periodic table are called periods.
The length of a period depends on how many electrons are needed to occupy the sublevels that fill the period. Blocks indicate which sublevel is being filled.
Why are s orbitals non directional? How many p-orbitals are occupied in a K atom? How many p-orbitals are occupied in a N atom? How many electrons can an f orbital have? How many electrons can there be in a p orbital? Students will first look at a diagram and animation to understand the basic pattern of the arrangement of electrons on energy levels around an atom.
Students will be given cards with information about the electrons and energy levels for each of the first 20 atoms. They will again try to correctly match the cards with each element. Students will be able to interpret the information given in the periodic table to describe the arrangement of electrons on the energy levels around an atom. Download the student activity sheet , and distribute one per student when specified in the activity.
Be sure that the 20 atom name cards are posted around the room. You will need the five cards on the right hand side of each sheet.
This lesson is intended as a follow-up to chapter 4, lesson 2. For Lesson 4. This is an online version of the periodic table card game from this lesson that you can assign as class work or homework after students have played the game in the classroom. Review with students that in lesson two they focused on the number of protons, neutrons, and electrons in the atoms in each element.
In this lesson, they will focus on the arrangement of the electrons in each element. Project the image Energy level cross-section. Explain to students that electrons surround the nucleus of an atom in three dimensions, making atoms spherical.
They can think of electrons as being in the different energy levels like concentric spheres around the nucleus. Since it is very difficult to show these spheres, the energy levels are typically shown in 2 dimensions.
Read more about energy level models in the teacher background section. Tell students that this energy level model represents an atom. The nucleus is represented by a dot in the center, which contains both protons and neutrons. The smaller dots surrounding the nucleus represent electrons in the energy levels. Let students know that they will learn more about electrons and energy levels later in this lesson. Have students look at the Periodic table of the elements 1—20 they used in lesson 2 to answer the following question:.
Show students that you have 80 cards 4 for each of the first 20 elements. Before distributing the cards, explain that each card contains information about electrons and energy levels for the first 20 elements of the periodic table. Remind students that they will need to count the electrons in order to identify each atom. Once students understand what their assignment is, distribute the cards to groups. After all cards have been placed at the 20 different atoms, select two or three atoms and review whether the cards were placed correctly.
This review will help reinforce the concepts about the structure of atoms and help students determine the number of protons and electrons in each atom. Give each student a Periodic Table of Energy Levels activity sheet. This table contains energy level models for the first 20 elements. The electrons are included only for the atoms at the beginning and end of each period.
Project the image Periodic table of energy levels.
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