Bonding Ch 7 & 8

Ionic Need to know Valence electrons Octet rule Cations Anions Ionic compounds Obviously, you need both a cation and an anion to create one of these…remember, net charge = 0.

Ionic compounds Chemical formula: the kinds and #s of atoms that make up the smallest unit of a substance/cpd. Formula unit: lowest whole number ratio of the atoms making up a cpd. Properties: brittle, crystalline solids, generally high melting pts., Coordination number: # of atoms of opposite charge that surround an ion in the crystal structure Ionic cpds. will conduct a current

Metallic bonds Free sea of electrons…this is what allows the ductile and malleable nature to occur. 202: body-centered, face-centered, hexagonal close packed xl structures. Alloys: solutions

Molecules and cpds. Covalent bonds: sharing electrons to satisfy the octet rule. Again, remember, net charge =0. Diatomic molecule: molecule with 2 atoms. Diatomic elements: H, N, O, F, Cl, Br, I. Molecular cpds: lower MP & BP.

Molecular Formulas How many atoms of each element in a molecule of a given compound

Bonds Single bond: the sharing of 2 (aka 1 pair) of electrons between 2 atoms. Double bond: the sharing of 4 (aka 2 pairs) of electrons between 2 atoms. Triple bond: the sharing of 6 (aka 3 pairs) of electrons between 2 atoms. No, no quadruple bonds…sorry. 

More on bonds Sigma and pi bond discussion: 230-231 VSEPR: valence shell electron pair repulsion theory: orbitals hybridize as needed for capacity for electrons. 232-236