Notes

VOCABULARY SKILL
Stable: Not easily changed from one state to another
Symbol: A written sign that stands for something else

VALENCE ELECTRONS
-Number of Protons = Number of electrons
-Electrons found in different energy levels
--Valence Electrons: Electrons of an atom with the highest energy level
---The number of valence electrons in an atom determines its chemical properties
ELECTRON DOT DIAGRAMS
-Each element has a determined number of valence electrons
--Electron Dot Diagram: Diagram that shows the symbol for the element surrounded by dots that represent the valence electrons
BONDING
-Elements with 8 valence electrons tend to be stable
--Ne, Ar, Kr, & Xe are all examples
-Atoms form bonds to become stable
--H needs only 2 valence electrons to be stable
--Valence electrons are transferred between atoms in these bonds
--Chemical Bond: The force of attraction that holds atoms together as a result of the rearrangement of electrons between them

APPLYING THE PERIODIC TABLE
-The number of valence electrons increases left to right across periods
--Every period starts with 1 valence electron
--Each period except Period 1 ends with 8 valence electrons
--This is why groups possess similar properties
NOBLE GASES
-Period 18 elements are stable and unreactive
--This is because they have 8 valence electrons