1. Chemical Bonding

2. Covalent Bonds Formed when 2 atoms share electrons Occurs most often between nonmetals

3. Polar Covalent Bonds Unequal sharing of electrons Unequal sharing of electrons Electrons attracted more to atom with the higher electronegativity Electrons attracted more to atom with the higher electronegativity Electronegativity difference is between 0.4 – 1.7 Electronegativity difference is between 0.4 – 1.7 Polar Covalent Bonds dissolve in water Polar Covalent Bonds dissolve in water –Why? The light bulb doesn’t light up. The light bulb doesn’t light up.

4. Polar Covalent Bonds

5. Non-polar Covalent Bonds Equal sharing of electrons Electronegativity difference is between basically 0. Usually found between diatomic molecules – two of the same atoms Non-polar covalent bonds don’t dissolve in water. Can be a solid, liquid or gas Can be a solid, liquid or gas

6. Non-polar Covalent Bonds

7. 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 & Electronegativity –Typically are metals

8. Ionic Bonds (cont.) Anion = - charged particle Anion = - charged particle –Loves to accept electrons –High Ionization Energy & Electronegativity –Typically are nonmetals Electronegativity difference >1.7 Electronegativity difference >1.7

9. Ionic Bonds (cont.)

10. If a bond is ionic: If a bond is ionic: –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!

11. Metallic Bonds Bond formed between multiple metal atoms. Bond formed between multiple 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. In metals, p-orbitals and some d-orbitals are completely vacant and overlap each atom. In metals, p-orbitals and some d-orbitals are completely vacant and overlap each atom.

12. Metallic Bonds

13. Hydrogen Bonds Intermolecular forces – attraction between molecules Intermolecular forces – attraction between molecules Some hydrogen containing compounds are extremely polar Some hydrogen containing compounds are extremely polar –HF, H 2 O, NH 3 –Large electronegativity differences cause this The hydrogen atom in the molecule is attracted to the unshared pair of electrons on another molecule The hydrogen atom in the molecule is attracted to the unshared pair of electrons on another molecule

14. Hydrogen Bond Example:

15. 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.

16. Van der Waals Bond Example: