1. Chemical Bonding

2. Covalent Bonds Formed when 2 atoms share electrons

3. Polar Covalent Bonds Unequal sharing of electrons Unequal sharing of electrons Electrons attracted more to higher E.N. atom, electron density is greater around the atom with higher E.N. value Electrons attracted more to higher E.N. atom, electron density is greater around the atom with higher E.N. value Electronegativity difference range = 0.4 – 1.7 (for polar covalent bonds) Electronegativity difference range = 0.4 – 1.7 (for polar covalent bonds) Polar Covalent Bonds dissolve in water Polar Covalent Bonds dissolve in water The light bulb doesn’t light up. The light bulb doesn’t light up.

4. Non-polar Covalent Bonds Equal sharing of electrons Equal sharing of electrons Electronegativity difference range = 0.0 – 0.3 Electronegativity difference range = 0.0 – 0.3 Usually found between diatomic molecules – two of the same atoms Usually found between diatomic molecules – two of the same atoms Non-polar covalent bonds don’t dissolve in water. Non-polar covalent bonds don’t dissolve in water. Can be a solid, liquid or gas Can be a solid, liquid or gas

5. Ionic Bonds Electrical attraction between large numbers of cations and anions Electrical attraction between large numbers of cations and anions Ion = a charged particle Ion = a charged particle Cation = + charged particle Cation = + charged particle –Loves to give electrons away –Low Ionization Energy, Electron Affinity & Electronegativity –Typically are metals –Most metallic element = Fr

6. Ionic Bonds (cont.) Anion = - charged particle Anion = - charged particle –Loves to accept electrons –High Ionization Energy, Electron Affinity & Electronegativity –Typically are nonmetals –Most nonmetallic element = F

7. Ionic Bonds (cont.) If a bond is ionic: If a bond is ionic: – The compound is solid –The compound will fall apart (dissociate) into its original ions when dissolved in water –If a conductivity test is performed, the light bulb will… light!

8. Metallic Bonds Bond formed between 2 metal atoms. Bond formed between 2 metal atoms. Electrons are free to move within electron clouds of all metal ions = Electrons are free to move within electron clouds of all metal ions = Sea of Electrons Electrons are delocalized – they don’t belong to any one atom anymore. Electrons are delocalized – they don’t belong to any one atom anymore.

9. Hydrogen Bonding Intermolecular – attraction between molecules Intermolecular – attraction between molecules One molecule is polar and has Hydrogen in a H-F, H-O or H-N bond One molecule is polar and has Hydrogen in a H-F, H-O or H-N bond Other molecule has an unshared pair of electrons, usually F, O, N Other molecule has an unshared pair of electrons, usually F, O, N

10. Van der Waals Bonds These bonds are important for Noble Gases These bonds are important for Noble Gases Very weak bonds Very weak bonds Electrons of Noble Gases get shifted to one side causing it to attract a slightly positive atom that is nearby. Electrons of Noble Gases get shifted to one side causing it to attract a slightly positive atom that is nearby.