Atoms, Bonding and the Periodic TableMr. Johnston, Saigon South International School

Warm UpConduct flame tests on various compounds with a flame test. When an alkali metal is placed in a flame, it emits a certain color. In this activity, you will conduct flame tests on various compounds. Collect and analyze your data here.

Homework Rap: 3-2-1

Key Questions

● Why do atoms combine with others to form compounds?

● How does an element’s location on the Periodic table tell us about it’s valence electrons and ability to bond?

Key Points

1. Valence Electrons of an atom are those electrons that have the highest energy.

2. Valence Electrons are involved in chemical bonding.

3. The number of Valence Electrons in an atom determines the chemical properties of that element.

Electron Dot Diagrams● Elements have 1-8 valence

electrons in outer shell. ● Electron Dot Diagrams: Show

the # of Valence Electrons of an element on the Periodic Table.

● Each “dot” is one valence electron.

Bonding● Atoms are more stable if they have 8 valence electrons. Example: Argon,

Krypton, and Neon (Noble Gases) are stable, and non-reactive. Helium is stable with 2 electrons

● Atoms tend to form bonds so that they have 8 valence electrons and become more stable, although Hydrogen needs only 2 to become stable.

● When atoms bond, they may transfer valence electrons from one to another or they may be shared.

Activity #1

Bond the elements at your table with one another so that they’re stable

Activity #2Find your partner with whom you’re doing your “element” project. Reserach a compound that your element makes up. Create an “electron dot diagram” that shows how electrons are shared in this compound. Please note:● Valence electrons.● How many valence each element has by itself. ● A “picture” of your electron dot diagram after bonding.