WELCOME!! 1. Please be in your seats by the time the bell rings. 2. On your catalyst sheet you should be on October November 4 th.

5 MINUTES CATALYST Why do you suppose the atomic size of each element element is increasing as you go down the table?

4 MINUTES CATALYST Sketch and complete the Bohr model for Argon. Include valance electrons. Why do you suppose the atomic size of each element element is increasing as you go down the table?

. 3 MINUTES CATALYST Why do you suppose the atomic size of each element element is increasing as you go down the table?

CATALYST Why do you suppose the atomic size of each element element is increasing as you go down the table? 2 MINUTES

CATALYST Why do you suppose the atomic size of each element element is increasing as you go down the table? 1 MINUTE

TIME’S UP!!!!!

Catalyst Answer Why do you suppose the atomic size of each element element is increasing as you go down the table? As you move down the periodic table, an energy level is added to each row so the atom is increasing in size.

AGENDA Catalyst Families Notes Valence electron sheet

ANNOUNCEMENTS 1. See me for help

TODAY’S OBJECTIVE Today you will learn about the different types of families on the periodic table. HS-PS1-2: Create knowledge of reaction based on patterns of properties

Periodic Trends Elemental Properties and Patterns

The Periodic Law Atoms with similar properties appear in groups or families (vertical columns) on the periodic table. They are similar because they all have the same number of valence (outer shell) electrons, which governs their chemical behavior.

Atomic Radius There are several important atomic characteristics that show predictable trends that you should know. What is are a few we’ve discussed? Atomic Radius is the distance from the center of the nucleus to the outermost shell.

Atomic Radius The trend for atomic radius in a vertical column is to go from smaller at the top to larger at the bottom of the family. Why? With each step down the family, we add a new shell or energy level, making the atoms larger with each step.

Notice new shells or energy levels being added.

Atomic Radius The trend across a horizontal period is less obvious. What happens to atomic structure as we step from left to right? Each step adds a proton and an electron (and 1 or 2 neutrons). Electrons are added to existing shells or orbits.

Atomic Radius The effect is that the more positive nucleus has a greater pull on the shells or orbits. The nucleus is more positive and the electron cloud is more negative. The increased attraction pulls the cloud in, making atoms smaller as we move from left to right across a period.

Magnet Activity