IPC NotesIPC Notes

Stability in Stability in Bonding &Bonding &

Electron Dot Electron Dot DiagramsDiagrams

Chemical StabilityChemical Stability

Atoms combine in order to Atoms combine in order to become chemically stable.become chemically stable.

A chemically stable atom A chemically stable atom has a full outer shell of has a full outer shell of electrons.electrons.

Chemical StabilityChemical Stability

Atoms combine by Atoms combine by gaining, losing or sharing gaining, losing or sharing electrons.electrons.

A chemical bond is the A chemical bond is the force that holds atoms force that holds atoms together in a substance.together in a substance.

Chemical StabilityChemical Stability

All elements combine except All elements combine except for the noble gases (group for the noble gases (group VIII A). Why?VIII A). Why?

The noble gases are the only The noble gases are the only elements that already have a elements that already have a full outer shell of electrons.full outer shell of electrons.

Chemical StabilityChemical Stability

A compound consists of 2 or A compound consists of 2 or more elements chemically more elements chemically combined.combined.

A chemical formula shows the A chemical formula shows the elements that a compound elements that a compound contains and the number of contains and the number of atoms of each element.atoms of each element.

Chemical StabilityChemical Stability

A subscript shows the A subscript shows the number of atoms of an number of atoms of an element in a compound.element in a compound.

ex) Hex) H22OO

Chemical StabilityChemical Stability

Valence electrons are the Valence electrons are the electrons in the outer electrons in the outer energy level of an atom.energy level of an atom.

Valence electrons are Valence electrons are responsible for chemical responsible for chemical bonding.bonding.

Chemical StabilityChemical Stability

An elements number of An elements number of valence electrons is the valence electrons is the same as the group number.same as the group number.

This is why elements in the This is why elements in the same group are chemically same group are chemically similar.similar.

Oxidation NumbersOxidation Numbers

An elements oxidation number An elements oxidation number is the charge that an atom is the charge that an atom has after gaining or losing has after gaining or losing electrons to become stable.electrons to become stable.

The oxidation number is The oxidation number is determined by the group determined by the group number.number.

Oxidation NumbersOxidation Numbers

The metals on the left side of The metals on the left side of the periodic table will lose the periodic table will lose electrons to have a positive electrons to have a positive oxidation number.oxidation number.

The nonmetals on the right The nonmetals on the right side of the periodic table will side of the periodic table will gain electrons to have a gain electrons to have a negative oxidation number.negative oxidation number.

Memorize the Charges!Memorize the Charges!

Electron Dot DiagramsElectron Dot Diagrams

An electron dot An electron dot diagram shows the diagram shows the valence electrons for valence electrons for an atom.an atom.

First, write the symbol First, write the symbol for the element.for the element.

Drawing Dot DiagramsDrawing Dot Diagrams

Then, put a dot to Then, put a dot to show each electron in show each electron in the outer shell, in the the outer shell, in the following order:following order:

X 36

47581 2

The reason for this The reason for this order is complex and order is complex and will be covered when will be covered when you take Chemistry.you take Chemistry.

Drawing Dot DiagramsDrawing Dot Diagrams

boronboron

neonneon

nitrogennitrogen

phosphorusphosphorus

sodiumsodium

chlorinechlorine