Ionic & Covalent Bonds

ObjectivesBe able to explain why atoms

sometimes join to form bondsBe able to explain why some atoms

transfer their valence electrons to form ionic bonds and others share valence electrons to form covalent bonds

Be able to differentiate between ionic, covalent, and metallic bonds

Compare the properties of substances with different types of bonds

Important VocabularyStable electron configurationIonic bondMetallic bondCovalent bondPolar covalent bondDipoleNon-polar covalent bondPolyatomic ions

What Holds Bonded Atoms Together?

1. A stable electron configuration

2. Bonds can bend without

breaking

3. Bonds can stretch without

breaking

Stable Electron Configuration

Happens when atoms have full outermost s & p orbitals

Bonded atoms also have electron configuration structures similar to noble gases

Bonds can Bend & Stretch

Bonds are not completely rigid

Many act like flexible springs in which the distance of the nuclei of the atoms changes

Types of BondsIonic

Metallic

Covalent

Polar

Non polar

Polyatomic Ions

Ionic BondsAre formed between oppositely

charged ionsThey are formed by the transfer of

electrons, one atom loses electrons and the other gains electrons i.e. Na+ + Cl- = NaCl

Ionic compounds are in the form of ion networks NOT molecules

Ionic compounds when melted or dissolved in water can conduct electricity

Ionic Bonds

Metallic BondsIs a bond formed by the attraction

between positively charged metal ions & the electrons around them

Electrons move freely between metal atoms

Attractive forces between nuclei and neighboring atom’s electrons pack the atoms close together, overlapping the energy levels

Metallic Bonds

Covalent Bonds

Compounds made of molecules have covalent bonds

Often formed between nonmetalsCan be solids, liquids, or gasesShare electronsCan share more than 1 electron2 main types:

Polar covalent bondsNon polar covalent bonds

Polar Covalent BondsAre when 2 different atoms share

electrons, but the sharing is not equalThis creates a dipole, a set of partial charges

Non Polar Covalent BondsOccur when electrons are shared

equallyIt can happen between atoms of the same

element or atoms of two different elements

Double & Triple Covalent Bonds

Polyatomic IonsAre made of groups of

covalently bonded atoms that have lost or gained electrons

In other words, they have both ionic and covalent bonds

We use parentheses to group the atoms of a polyatomic ion (NH4)2SO4

The charge of a polyatomic ion applies to the entire ion