Learning objectives

Electronegativity			H 2.2					He
Li 1.0	Be 1.6		B 2.0	C 2.6	N 3.0	O 3.4	F 4.0	Ne
Na 0.93	Mg 1.3		Al 1.6	Si 1.9	P 2.2	S 2.6	Cl 3.2	Ar
K 0.82	Ca 1.0		Ga 1.6	Ge 1.8	As 2.2	Se 2.6	Br 3.0	Kr
Rb 0.82	Sr 0.95		In 1.8	Sn 2.0	Sb 2.1	Te 2.1	I 2.7	Xe
Cs 0.79	Ba 0.89		Tl 1.6	Pb 2.3	Bi 2.0	Po 2.0	At

Electronegativity is a measure of the tendency of a bonded atom to attract electrons to itself.  The Pauling scale of electronegativities for Groups 1, 2 and through  of the periodic table shows how electronegativity depends on the position of the element in the periodic table. 

On completion of the module you should be able to
 

• use periodic trends in electronegativity to choose the most (or least) electronegative element from a set of elements
   
• use electronegativity differences to predict whether bonding between atoms in a binary compound is ionic or covalent
   
• use electronegativity differences to identify the most (or least) polar covalent bonds
   
• use relative electronegativities to deduce the direction of bond polarisation