Lewis structures

• Groups 1-4 make enough bonds to lose all their valance electrons
• Groups 5-7 make enough bonds to fullfill the octet rule
• Octet rule

  All atoms should have 8 valance electrons to be stable
• Group 5-7 want electrons because they are more electronegative so when they form a bond with a group 1-4 element that is less electronegative; when their bond breaks, all the electrons in the bond goes to the Group 5-7 element
• Incomplete octets

  When an element has no choice but to have less than 8 valance electrons- usually when an element with a small atomic number is forced to be a central element

  ex. BH3, Boron has only 6 valance electrons after bonding
• 2nd row elements

  Can only have incomplete or complete octets because of their sub-level (2) only allows them to have up to 8 electrons
• 3rd and below row elements

  Can have expanded or complete octets because their sub level (3) allows them to have up to 18 electrons (3s^2, 3p^6, 3d^10)
• When two elements are bonding and there is a choice between which element to satisfy the octet rule with and which element to leave incomplete, the more electronegative element will draw the most electrons; hence they will have the expanded octet or the completed octet but not the incomplete octet as they pull electrons to them.
• The best lewis structure for a compound is the one in which the central atom has a formal charge of 0
• Formal charge = valance electrons - (# of bonds + lone electrons (NOT PAIRS))
• Octet rule exception: Boron likes 6, Hydrogen likes 2
• VSEPR is the valance shell electron pair repulsion theory and tells us how molecules like to be formed
• Molecular geometry is the amount of bonds a compound has while electron geometry (domain) is the amount of bonds + lone pairs a compound has
• Naming ethers: smaller molecule + "oxy" + larger molecule + "ane"
• Naming esters: side chain + "yl" + molecule with ester group + "oate"