Warm-UpWarm-UpWhich metals are the most reactive?Which metals are the most reactive?– Alkali metalsAlkali metals

Which non metals are the most reactive?Which non metals are the most reactive?– HalogensHalogens

Why don’t metals in group 1A have identical Why don’t metals in group 1A have identical properties?properties?– Elements in group 1A don’t have identical Elements in group 1A don’t have identical

properties because their valence electrons are in properties because their valence electrons are in different energy levels.different energy levels.

4-1 Ions & Ionic Bonding4-1 Ions & Ionic BondingRecognizeRecognize stable electron configurations.stable electron configurations.

PredictPredict an element’s chemical properties an element’s chemical properties using number of valence electrons and using number of valence electrons and electron dot diagrams.electron dot diagrams.

Stable Electron ConfigurationStable Electron ConfigurationThe highest occupied energy level of an The highest occupied energy level of an atom is filled with electrons.atom is filled with electrons.

Nobel gases have 8 valance electrons Nobel gases have 8 valance electrons (He-2).(He-2).

The highest energy level is completely full.The highest energy level is completely full.

Noble gases are colorless, odorless, and Noble gases are colorless, odorless, and un-reactiveun-reactive..– Very few compounds form with Nobel gases.Very few compounds form with Nobel gases.

Electron-Dot DiagramElectron-Dot DiagramA model of the atom to represent the A model of the atom to represent the valence or outer shell electrons.valence or outer shell electrons.

The number of dots = number of valence The number of dots = number of valence electrons.electrons.

The symbol in the center represents the The symbol in the center represents the nucleus and all other electrons.nucleus and all other electrons.

Electron dot diagram helps to determine Electron dot diagram helps to determine stability.stability.

Formation of IonsFormation of IonsAtoms that lose or gain electrons are Atoms that lose or gain electrons are called called ionsions..

Ions are charged atoms.Ions are charged atoms.

Ions have unequal numbers of protons Ions have unequal numbers of protons and electrons.and electrons.

Charge can be positive or negative.Charge can be positive or negative.

Ions are formed because atoms want to Ions are formed because atoms want to have a stable electron configuration.have a stable electron configuration.

Types of IonsTypes of IonsPositive ionsPositive ions– Lose electrons or lose negative charge.Lose electrons or lose negative charge.– Subtracting negatives = positives.Subtracting negatives = positives.– Atoms that have lost electrons are called Atoms that have lost electrons are called

cations (“cat-ions”)cations (“cat-ions”)– MetalsMetals

Negative IonsNegative Ions– Gain electrons or gain negative charge.Gain electrons or gain negative charge.– Atoms that have gained electrons are called Atoms that have gained electrons are called

anion (“ant-ion”).anion (“ant-ion”).– NonmetalsNonmetals

NaNa++ AlAl3+3+

KK++

MgMg2+2+

CaCa2+2+

NN3-3- FF--

PP3-3-

OO2-2-

SS2-2- ClCl--

Ionic BondsIonic BondsChemical bondsChemical bonds is a force that holds is a force that holds atoms together as a unit.atoms together as a unit.– Ionic bondsIonic bonds are the cations being attracted to are the cations being attracted to

the anionsthe anions– Particles with opposite charges are attracted.Particles with opposite charges are attracted.

Ionic bonds are formed when atoms Ionic bonds are formed when atoms transfer electrons from one atom to transfer electrons from one atom to another.another.

Ionic CompoundsIonic CompoundsCompounds are substances that contain Compounds are substances that contain more than one atom in chemical ratios.more than one atom in chemical ratios.

The ratio is known as the chemical The ratio is known as the chemical formula.formula.

Ions don’t bond in random ways. Ions don’t bond in random ways.

Ion will bond with the number of atoms to Ion will bond with the number of atoms to give a full shell of electrons.give a full shell of electrons.

Ions also bond to balance charges.Ions also bond to balance charges.

SummarySummaryWhat happens to atoms when they form What happens to atoms when they form ionic bonds?ionic bonds?– One atom in the compound had to loose an One atom in the compound had to loose an

electron and one atom in the compound had electron and one atom in the compound had to gain an electron.to gain an electron.

What type of elements form ionic bonds?What type of elements form ionic bonds?– Metal and nonmetalMetal and nonmetal