CHEM 121 Lecture Notes - Lecture 5: Pentane, Butane, Chemical Formula
Document Summary
Molecular compounds are typically formed between two non-metals. Chemical bonds are the sharing or transfer of valence electrons. How do you tell the difference: compounds show very different behaviour, melting and boiling points, gauge sharing with electronegativity. The only exception where a molecular formula contains metals is when nh4 is involved. Non-metals share enough electrons to complete an octet (or duplet) The ones who have the lower electronegativity will be the central atom. Some atoms have extra room for valence electrons. Resonance means that there"s the same atom arrangement but different electron pair arrangement. Keeps track of how many electrons the atom in a molecule has access to. If an atom has access to fewer electrons than it"s happy number, it will have a positive formal charge. If an atom has access to more electrons that it"s happy number, it will have a negative formal charge. Lone pair + 1/2 bonded pair (lp +1/2bp)
