Lesson 6: The Recurring (Periodic) Table of Elements

In this first activity, you will be introduced to some basic information about the elements found on the periodic table. You will be looking at atomic number, atomic mass, and electron configuration (specifically the number of electrons on the outer shell). You will then complete a couple of activities that will help reinforce your understanding. NOTE: A full-color copy of the periodic table has been included with this unit. You should have it handy to refer to as needed.

Consider the "Carbon Example" graphic. The atomic number, which represents the number of protons in the element, is at the top of the information square. The name of the element is above the atomic number. The atomic mass of the element is at the bottom. In between each number is the shorthand abbreviation or symbol for each element.

Keep in mind the following information about the parts of the atom:

Using the information provided, complete the "Organization of the Periodic Table" page by filling in the missing information for each element in the table. After you complete the table, use the information to fill in the five blocks at the bottom of the page. Refer to the "Carbon Example" graphic as needed.

In this activity, think back to the beginning of the unit when you worked on atomic structure and learned about the number of electrons on the outer shells of each element.

On the "Periodic Table and Atomic Structure" page, you will write the number of electrons present for each shell that is used. For example, helium has two electrons. They fill the first shell, so you will write "2" in the "n=1" column. If helium had three electrons, you would write 2 for the first shell and 1 for the second shell.

As you recall, each atom has orbitals (also called shells). In the list below and on the activity page, "n" represents which orbital is represented. The label n=1 represents the orbital closest to the nucleus; n=2 equals the orbital that is second closest, etc. Each orbital can hold a maximum number of electrons:

*Note that although the 3rd orbital can hold a maximum of 18 electrons, the 4th orbital begins to fill before the 3rd orbital is full. For the elements we'll look at in this unit, the 3rd orbital will hold up to 8 electrons. After the 3rd orbital has 8 electrons, it is considered full, and the 4th orbital will begin filling. In high school chemistry, you will learn that the rules for filling shells 3 and 4 are more complicated for some elements.

Use the information about each orbital to complete the activity page. Remember that the number of electrons is equal to the number of protons. Once one orbital is full (has its maximum number of electrons), start filling the next orbital (the exception being the third shell — once it contains 8 electrons, you start filling the 4th orbital).

Hold on to your activity sheets. You will use them in other parts of the lesson, and you will use information from the table for your final activity.