Atoms, elements, and the periodic table

Lesson Outline Categorizing the periodic table Group-related periodic patterns Period-related periodic patterns Question of the day Lewis dot structures

Specific Expectations B2.2 analyze data related to the properties of elements within a period to identify general patterns in the periodic table. B3.3 state the periodic law, and explain how patterns in the electron arrangement and forces in atoms result in periodic trends V1.2 reframe from shouting out answers. Raise your hand before participating to allow all other students the equal right to participate.

The Periodic Law States that the chemical and physical properties of the elements repeat in a regular, periodic pattern when they are arranged according to their atomic size.

Periodic Table Handout 1. Identify the following on the front side of the periodic table handout: Metals and non metals Metalloids (staircase) Transition metals Alkali metals Alkaline earth metals Halogens Noble Gases 2. Define and note the importance of the following in your course notes: Metalloids Transition metals Alkali metals Alkaline earth metals Halogens Noble Gases

Patterns based on energy levels and electron arrangements The Period-related pattern Rows that run horizontally on the periodic table are known as periods. Every period on the periodic table identifies the number of electron energy shells that each element contains. As you go down the periodic table, elements contain more electron energy shells. Note Periods on the backside of the handout! Increasing energy shells

Question of the day!?!?! If a 1/4 slice of pie is 3 times larger then all other slices in the pie, how many slices are in the pie?

Lewis Dot structures Lewis Dot structures: represent elements and the valence shell electrons of their atoms Rules for drawing Lewis Dot Structures: 1.Replace the nucleus of the atom with the atomic symbol of the element. 2.Determine the number of valence shell electrons in the element. 3.Electrons are only placed at the north, east, south, and west section around the atomic symbol. 4.Place electrons in a clockwise fashion around the atomic symbol, starting at the north. Ex. Na and Cl Work through handout

The group-related pattern Colum's on the periodic table are known as groups! Groups run from left to right on the table (IA-VIIA). Valence shell electrons: The electrons that occupy the outer energy shell of an atom. As you travel from left to right on the periodic table (excluding the transitions metals) elements have an increasing number of valence shell electrons. Increasing valence shell electrons

Stable octet rule: When atoms have eight electrons in the outer energy shell (or two for hydrogen or helium) it is known as a stable octet. All atoms want to have a full outer shell of electrons because it is stable! Atoms can gain or lose electrons, pending on what is an easier method to obtain a full outer shell. When they do so, the will acquire a charge because of the new difference in amounts between protons and electrons. Ex. Lithium List all group charges on the backside of the handout Note: when considering the group charge pattern, it is best to use the second period Lithium  Neon