Electronegativities Periodic Table of the Elements

Periodic Table with Electronegativities

 

Electronegativity is defined as the ability of an atom in a molecule to attract electrons to itself. The electronegativity of an atom in a molecule is related to the atom's ionization energy and electron affinity, which are properties of isolated atoms. An atom with a high ionization energy and with a very negative electron affinity both resists having its electrons attracted away and attracts electrons from other atoms. It is highly electronegative.

Linus Pauling developed the first and most widely used electronegativity scale which is based on thermochemical data (Table 1). There is generally an increase in electronegativity from left to right across a row of the periodic table. Electonegativity decreases -with a few exceptions like the transition metals - with increasing atomic number or from up to down in a row of the periodic table.

Electronegativities are used to estimate whether a given bond is covalent, polar covalent, or ionic.

 

Table 1: Periodic Table with Electronegativities

1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17
H 2.1
Li 1.0	Be 1.5											B 2.0	C 2.5	N 3.0	O 3.5	F 4.0
Na 0.9	Mg 1.2											Al 1.5	Si 1.8	P 2.1	S 2.5	Cl 3.0
K 0.8	Ca 1.0	Sc 1.3	Ti 1.5	V 1.6	Cr 1.6	Mn 1.5	Fe 1.8	Co 1.9	Ni 1.9	Cu 1.9	Zn 1.6	Ga 1.6	Ge 1.8	As 2.0	Se 2.4	Br 2.8
Rb 0.8	Sr 1.0	Y 1.2	Zr 1.4	Nb 1.6	Mo 1.8	Tc 1.9	Ru 2.2	Rh 2.2	Pd 2.2	Ag 1.9	Cd 1.7	In 1.7	Sn 1.8	Sb 1.9	Te 2.1	I 2.5
Cs 0.7	Ba 0.9	La 1.0	Hf 1.3	Ta 1.5	W 1.7	Re 1.9	Os 2.2	Ir 2.2	Pt 2.2	Au 2.4	Hg 1.9	Tl 1.8	Pb 1.9	Bi 1.9	Po 2.0	At 2.2
Fr 0.7	Ra 0.9	Ac 1.1	Th 1.3	Pa 1.4	U 1.4	Np 1.4

 

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References

1. CRC Handbook of Chemistry and Physics, 52nd edition, The Chemical Rubber Co., (1971)
2. David W. Oxtoby, H.P. Gillis, Alan Campion, “Principles of Modern Chemistry”, Sixth Edition, Thomson Brooks/Cole, 2008
3. Steven S. Zumdahl, “Chemical Principles”  6th Edition, Houghton Mifflin Company, 2009

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Key Terms

electronegativity, electronegativity difference, electron affinity, ionization energy, Pauling,

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