AP Chem Compound Structure and Properties Unit 2

Ionic compounds 

metal + nonmetal

ionic compounds are usually

Brittle, have high melting points

ionic compounds conduct electricity when

dissolved into solution

covalent compounds

non-metals + non-metals

covalent compounds conduct electricity 

never 

Polar Covalent Bonds 

nonmetals are “hogging” the electrons 

Non-polar covalent bonds

both non-metals are sharing electrons equally (or almost)

The farther away electrons are

the higher potential energy there is

The closer electrons are

the lower potential energy there is

Single bonds are the 

weakest and the longest

triple bonds are the

strongest and the shortest

In a crystal lattice

positive ions are smaller and negative ions are larger

Metallic bonding exhibit

delocalized valance electrons that basically float around

Metals conduct electricity so well because they have

free floating electrons

Substiutional Alloys 

formed when atoms of the added element substitute some of the metal atoms in the structure

Substiutional Alloys must be

about the same size

Interstitial Alloy

Formed when small atoms fit into the spaces (interstices) between the larger metal atoms 

a single bond is composed of

1 sigma

a double bond is composed of

1 sigma & 1 pi

a triple bond is composed of 

1 sigma & 2 pi 

The hybridization is sp if

2 atoms are surrounded around the central atom

The hybridization is sp2

3 atoms are surrounded around the central atom

The hybridization is sp3 if

4 atoms are surrounded around the central atom

Linear molecular geometry has a bond angle of 

180 degrees 

Trigonal Planar has a bond angle of 

120 degrees 

Tetrahedral has a bond angle of

109.5

Trigonal Bipyramidal has a bond angle of

90 degrees & 120 degrees

Octahedral has a bond angle of

90 degrees

Trigonal Planar 

tetrahedral

trigonal Bipyramidal

Octahedral

The best representation for a structure to have is to have a

formal charge of zero

geometries that cancel out (non polar) 

linear, trigonal planar, tetrahedral, trigonal bipyramidal, Octahedral

geometries that don't cancel out ( polar) 

Bent, Trigonal Pyramidal, Seesaw, T-Shaped

brittleness is due to

internal repulsion of ion layers within the crystal lattice, moving adjacent layers

interstitial Alloys are smaller or bigger than the spaces they occupy

smaller

Malleability shows what

how adjacent layers of positive ions can move relative to one another while remaining in full contact with the electron sea

Formal charge equals 

Valence electrons - non-bonding valance electrons - bonding electrons

4 electron domains has what molecular geometry?

tetrahedral

3 electron domains has what molecular geometry?

trigonal planar

2 electron domains has what molecular geometry?

linear