chem bonds

properties of metals

1\. exist as solids at room conditions (except for Hg(1))

2\. high melting and boiling points

3\. can conduct heat and electricity in any state

4\. malleable and ductile → pulled into wives

ionic bonds

e- are transferred from metal to nonmetal

properties of ionic compounds

1\. exist as crystalline solids

2\. high melting and boiling points

3\. can conduct electricity in molten or aqueous state

4\. brittle → breaks, doesn’t bend

5\. most soluble in polar solvents

properties of molecular compounds

1\. typically exist as gases, liquids, or amorphous solids

2\. low melting and boiling points

3\. poor conductors (insulators)

4\. most soluble in nonpolar solvents (usually not soluble in polar solvents i.e. H2O)

nonpolar bond

\- electrons are shared equally

\- difference in electronegativity from 0.0-0.3

polar bond

\- electrons are shared unequally

\- difference in electronegativity from 0.4-1.7

nonpolar molecules

\- all bonds are nonpolar symmetrical polarity cancels out

\- completely symmetrical w.r.t. central atom (central atom will only have bonds and only to one element)

polar molecules

asymmetrical w.r.t. central atom (central atom has LP or 2 kinds of elements bonded to it)

london dispersion force (LDF)

\- present in ALL compounds (and strongest elements)

\- due to motion of electrons

\- partial charges created temporarily (induced dipole)

dipole-dipole

\- present in polar molecular compounds

\- attraction between partial charges of 2 different molecules

hydrogen bonding

\- misnomer-not actually a type of “bond”

\- present in some polar molecular compounds

\- H must be bonded to N,O, or F

\- Those H’s are sites where H-bonding can take place; more sites for H-bonding means stronger H-bonding