# Lesson 6: The Recurring (Periodic) Table of Elements

## Wrapping Up

### Conclusion

In the two days of this lesson you have made a connection between the atomic structure of each element and patterns that are emerging that lead to recognized differences between nonmetals and metals. As you work on the final project for this unit (which will be a more detailed look at the periodic table and the elements that are all around you at home) keep in mind that these patterns are consistent no matter how much or how little of an element is present. You can count on the fact that carbon (atomic number 6) will in its natural form not have more than four electrons on its outer shell. You can be confident that potassium (K, Atomic number 19) will always be a metal and that its outermost shell will have one electron on its outermost shell.

These last two lessons have been a challenge. Go back and look at them if you are not sure about any concepts. Make sure that you understand that different shells have different numbers of electrons. Make sure that you understand the differences between nonmetals and metals.

### Questions to Discuss

• Using the table completed in Activity 2, what elements are inert gases? How do you know? (Helium, neon, argon; because the outermost shells of each one is full.)
• What trends do you notice with regards to the outer shells of nonmetals? (Nonmetals tend to have shells that are full -- as with inert or noble gases -- or almost full.)
• What differences do you see between the outer shells of metals and nonmetals? (Metals tend to have fewer electrons on their outermost shells; metals tend to have less than 4, and nonmetals tend to have 4 or more.)

### Things to Review

• Understand that all matter is made up of atoms and that atoms of the same element are all alike.
• Know that atoms of one element are different from the atoms of other elements at the most basic level.
• The periodic table is a way to classify elements based on their properties.
• Recognize that the organization of the periodic table is based on the atomic structure of the atoms of each element.
• General trends on the periodic table include that nonmetals tend to have more electrons on their outermost shells, and metals tend to have fewer electrons on their outermost shells.