Ionic BondingIonic Bonding

Chapter 15 Chapter 15

Sections 1 and 2Sections 1 and 2

Sodium is always willing to help.Sodium is always willing to help.

Alkali Metal

Valence ElectronsValence Electrons

Electrons in the highest occupied energy Electrons in the highest occupied energy level of an atomlevel of an atom

Explain why atoms combine in the ratios Explain why atoms combine in the ratios that they do.that they do.

Determine the chemical propertiesDetermine the chemical properties

The number of The number of valence electrons valence electrons is related to the is related to the group numbergroup number

This is so

easy!

Electron Dot structuresElectron Dot structures– Shows the valence electrons as dots around the Shows the valence electrons as dots around the

symbolsymbol

Octet RuleOctet Rule

The electron configurations of the Noble The electron configurations of the Noble Gases usually involves 8 electronsGases usually involves 8 electrons

– Atoms bond and form ions in an attempt to Atoms bond and form ions in an attempt to achieve a full octetachieve a full octet

– Ionic charge is associated with the valence Ionic charge is associated with the valence electronselectrons

The only absolute in chemistry is that there is The only absolute in chemistry is that there is always an exception!always an exception!

Except He, compounds involving an odd # of Except He, compounds involving an odd # of electrons, Boron, Phosphorous, Beryllium and electrons, Boron, Phosphorous, Beryllium and SulfurSulfur

The transition elements will not achieve a Noble The transition elements will not achieve a Noble Gas configuration because of the “d” orbitalsGas configuration because of the “d” orbitals

Space Ghost Says:

Ionic BondsIonic Bonds The force of attraction between cations and The force of attraction between cations and

anions.anions.– Electrostatic attractionElectrostatic attraction

Positive charge must = Negative chargePositive charge must = Negative charge– Ionic formula shows the lowest whole number Ionic formula shows the lowest whole number

ratio of cations to anionsratio of cations to anions– Electrons are given by the cation to the anionElectrons are given by the cation to the anion

Unit CellUnit Cell– The smallest group of particles within a crystal The smallest group of particles within a crystal

that retains the shape of the crystalthat retains the shape of the crystal

PropertiesProperties Coordination number – the number of ions Coordination number – the number of ions

of opposite charge that surround the ion in a of opposite charge that surround the ion in a crystalcrystal

Na in NaCl = 6Na in NaCl = 6

Non-ductileNon-ductile Non-malleableNon-malleable