Summary Chemical Bonds Notes

-Chemical_ Bonding

-CovalentBonds-

Bonds between
·

2 non-metals


Sharing of electrons
·




Electronegativity : Measure of the tendency of
on atom to attract a
bonding pair of electrons




Non =Polar-


Equal sharing of electrons
·




No difference
electronegativity
·

in


LEn less than
·

= 0 . 4




-Polar Bands


Unequal Sharing of
·

electrons

Difference
·

in
electronegativity
Forms
-




dipole

Greater difference = more polar

·En = 0 . 4-1 .
7




-Eani?_Bonds


Bonds between
·

metal and non-metal
·
Transfer of electrons




Metal donates its
·

electron

-


Forms a cation

Non-metal accepts
·

electron

-


Forms anion




forces
Causes
strong
·

electrostatic

-



Forms a
giant ionic crystal lattice


Metallic_ Banding-

Bond between metals
·

2

·
Form between positive kernels in a sea of delocalised electrons
·

Smallest particle = positive core ion


Delocalised to from
·

electron moves and each atom




-Polarity -




Yes
Are & Es the No Molecule
covalent bonds polar? molecule ⑭ is



No symetrical Polar
⑭
Yes
Molecule is non-polar a

, Determing Polarity _
-




-Non-polar-


Any monoatomic
·

molecule

Includes diatomic elements
-




Any
·


carbon
molecule with only and
hydrogen
CH4 Calo CHz = CHz
-




; ;




Symetrical
·

molecules


Always non-polar
-




Asymetrical
·

molecule


Only non-polar if DEN less than 4
-



is 0 .




Polar-


Any hydrogen bond
·




-

H -
N ,
0 ,
F

-


Hz0 ; NHe




Asymetrical
·




-Polar if DEN than
is
greater 0 4
.