CATEGORY ： Chemistry 12 Typical Table 2007/03/15 Thu TB ： CM ： 0 △

Bond Type	Generally Formed Between	Bond Formed By	Properties Associated with bond type	Example of substances Utilizing bonf type
Covalent	Atoms of non-metallic elements of similar electronegativity	Sharing of electron pairs	Stable non ionizing molecules-not conductors of electricity in any ohase	C2H5
Ionic	Atoms of metallic and non-metallic elements of wide.y different electronegativities	Elec. attraction between ions resulting from transfer of electrons fron one to another	Charged ions in gas liwuid and soid. Sokid is electrically non- sonducting. Gas and liquid are condustors	NaCl, K2O, BaS, LiH
Metallic	Atoms of metallic elements	Common exchange of outer electrons between atons of low electronegativity	Electrical conductors in all ohases, luster	Na, Au, Cu. Zn
Dipole	Polar covalent molecules	Electrical attraction between dioples resulting from polar bonds	Substances have higher boiling and melting points than those having non-polar molesules of similar size	ICl, SO2
Hydrogen	Molecules having hydrogen attached to atim of high electronegativity	Attraction of exposed proton to electronegative atom in neigh boring molecule	substances have mush higher boiling and melting points than those having non-polar molecules of similar size	H2O, HF
Dispersion Forces	Non polar molecules	Weak electrical fluctuations which destroy spherical symmetry of electronic fields about atoms	Substanve have soft crustals and comparaticeley low melting and boiling points	He, Ar, Cl2,CH4

Special covalent

NETWORK CRYSTAL - carbon, silicon - HIGH m.p. S₁C₂, C, S₁O₂

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substance	Melting Point (℃)	Boiling point (℃)	Reason
C2	2700	-	Networl Crystal
Au	1063	2807	Metallic
NaF	988	1695	Ionic
NaI NaOH	651 318	1300(May Decompose) 1300(may Decompose)	Electronegativity
H2O	0	100	Hydrogen Bonding
HI HBr	-50 -88	-35(Dipolar) -65(Dipolar)	Molar Mass
Ne He	-248 -272	-246(London) -269(london)	Molar Mass

Except N->Ne


The above are general nrules which are useful BUT there are exceptions.

Nonpolar molecules like CH₄, CCl₄, etc are placed with the London forces because of their shapes, they are nonpolar and have no dipolar forces. As the molar mass increases, so does the attraction (easier to induce a dipole) therefore their melting points also tend to rise.
Pridict the type of conding that is displayed in the following substances

Xe London	ICl Dipolar	CO2 London	HF H.B.
NaBr Ionic	HI Dipolar	CH4 London	CO Dipolar
S1O4 Network Crystal	diamond (C) Network Crystal	CH3Cl	CaCO3 Ionic
O2 London	NH3 Hydrogen	N2H6 Hydrogen Bonding	CS2 London
H2O Hydrogen Bonding	Fe Metallic	Pt Metallic	SO2
F2 London	SuO2 Network	H2O2 Hidrogen Bonding	CCl4 London

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VSEPRT (Valence shell electron pair repulsion)

Basic Shapes:

1. Collinear (linear triatomic)

2. Traiangular Planar

3. Tetrahedral

4. Triangular Pyramidal

5. Angular