Exploring the Periodic Table Section 2 Exploring the Periodic Table

Learning Targets I can explain why atoms form ions. I can determine the ion formation of an element. (worksheet) I can differentiate between nonmetals, metals and metalloids.

The Role of Electrons The periodic trends in the periodic table are the result of electron arrangement Chemical properties are determined by , which are . Elements in a group have chemical and physical properties in common because they have the same number of . valence electrons located in the outermost energy level valence electrons

An element’s electron arrangement determines its location in the periodic table

Ion Formation

Ions What is an ion? An atom with a charge (+ or -) Why do atoms form ions? To have a filled outermost energy level How does an atom become an ion? Atoms gain or lose e- What electron configuration does an ion possess? Electron configurations like noble gases full shell = stable 

Octet Rule Elements lose, gain, or share electrons to form the required octet in their highest remaining energy level.

Ion formation How to make Li look like He? LOSE AN ELECTRON! Li He 3p+

Equation of ion formation + Li 3p+ Li 3p+ + Li  Li+ + 1e- CATION = atom with a POSTIVE charge

Ion formation How to make O look like Ne? GAIN 2 ELECTRONS! O Ne 8p+

Equation of ion formation 2- O 8p+ O 8p+ + O + 2e-  O2- ANION = atom with a NEGATIVE charge

How are Elements Classified?

Metals Most of the elements Shiny Malleable can be pounded into thin sheets Conduct heat and electricity Ductile can be stretched into thin wires

Nonmetals Right side of periodic table Dull Brittle Poor conductors of heat and electricity (insulators) Not ductile or malleable Sulfur Graphite

Semiconductors Metalloids Conduct electricity under certain conditions Share properties with metals and nonmetals Ductile and malleable Solids that can be shiny or dull

Learning Target Checkpoint Why do atoms form ions? What is the difference between metals, nonmetals and metalloids?