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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