Electronegativities of the elements (data page) explained

Electronegativity (Pauling scale)

Number	Symbol	Name	data-sort-type="number"	use !	data-sort-type="number"	WEL !	data-sort-type="number"	CRC !	data-sort-type="number"	LNG
1	H		2.20	same
2	He		no data	same
3	Li		0.98	same
4	Be		1.57	same
5	B		2.04	same
6	C		2.55	same
7	N		3.04	same
8	O		3.5	same
9	F		3.98	3.98	3.98	3.90
10	Ne		no data	same
11	Na		0.93	same
12	Mg		1.31	same
13	Al		1.61	same
14	Si		1.90	same
15	P		2.19	same
16	S		2.58	same
17	Cl		3.16	same
18	Ar		no data	same
19	K		0.82	same
20	Ca		1.00	same
21	Sc		1.36	same
22	Ti		1.54	same
23	V		1.63	same
24	Cr		1.66	same
25	Mn		1.55	same
26	Fe		1.83	same
27	Co		1.88	same
28	Ni		1.91	same
29	Cu		1.90	same
30	Zn		1.65	same
31	Ga		1.81	same
32	Ge		2.01	same
33	As		2.18	same
34	Se		2.55	same
35	Br		2.96	same
36	Kr		3.00	3.00	no data	no data
37	Rb		0.82	same
38	Sr		0.95	same
39	Y		1.22	same
40	Zr		1.33	same
41	Nb		1.6	same
42	Mo		2.16	same
43	Tc		1.9	1.9	2.10	2.10
44	Ru		2.2	same
45	Rh		2.28	same
46	Pd		2.20	same
47	Ag		1.93	same
48	Cd		1.69	same
49	In		1.78	same
50	Sn		1.96	same
51	Sb		2.05	same
52	Te		2.1	same
53	I		2.66	same
54	Xe		2.6	2.6	2.60	no data
55	Cs		0.79	same
56	Ba		0.89	same
57	La		1.10	same
58	Ce		1.12	same
59	Pr		1.13	same
60	Nd		1.14	same
61	Pm		no data	same
62	Sm		1.17	same
63	Eu		no data	same
64	Gd		1.20	same
65	Tb		no data	same
66	Dy		1.22	same
67	Ho		1.23	same
68	Er		1.24	same
69	Tm		1.25	same
70	Yb		no data	same
71	Lu		1.27	1.27	1.0	1.0
72	Hf		1.3	same
73	Ta		1.5	same
74	W		2.36	2.36	1.7	1.7
75	Re		1.9	same
76	Os		2.2	same
77	Ir		2.20	2.20	2.2	2.2
78	Pt		2.28	2.28	2.2	2.2
79	Au		2.54	2.54	2.4	2.4
80	Hg		2.00	2.00	1.9	1.9
81	Tl		1.62	1.62	1.8	1.8
82	Pb		2.33	2.33	1.8	1.8
83	Bi		2.02	2.02	1.9	1.9
84	Po		2.0	same
85	At		2.2	same
86	Rn		no data	same
87	Fr		no data	0.7
88	Ra		0.9	same
89	Ac		1.1	same
90	Th		1.3	same
91	Pa		1.5	same
92	U		1.38	1.38	1.7	1.7
93	Np		1.36	1.36	1.3	1.3
94	Pu		1.28	1.28	1.3	1.3
95	Am		1.3	1.3	no data	1.3
96	Cm		1.3	1.3	no data	1.3
97	Bk		1.3	1.3	no data	1.3
98	Cf		1.3	1.3	no data	1.3
99	Es		1.3	1.3	no data	1.3
100	Fm		1.3	1.3	no data	1.3
101	Md		1.3	1.3	no data	1.3
102	No		1.3	1.3	no data	1.3

Notes

Separate values for each source are only given where one or more sources differ.
Electronegativity is not a uniquely defined property and may depend on the definition. The suggested values are all taken from WebElements as a consistent set.
Many of the highly radioactive elements have values that must be predictions or extrapolations, but are unfortunately not marked as such. This is especially problematic for francium, which by relativistic calculations can be shown to be less electronegative than caesium, but for which the only value (0.7) in the literature predates these calculations.

Electronegativity (Allen scale)

Number	Symbol	Electronegativity
1	H	2.300
2	He	4.160
3	Li	0.912
4	Be	1.576
5	B	2.051
6	C	2.544
7	N	3.066
8	O	3.610
9	F	4.193
10	Ne	4.787
11	Na	0.869
12	Mg	1.293
13	Al	1.613
14	Si	1.916
15	P	2.253
16	S	2.589
17	Cl	2.869
18	Ar	3.242
19	K	0.734
20	Ca	1.034
21	Sc	1.19
22	Ti	1.38
23	V	1.53
24	Cr	1.65
25	Mn	1.75
26	Fe	1.80
27	Co	1.84
28	Ni	1.88
29	Cu	1.85
30	Zn	1.588
31	Ga	1.756
32	Ge	1.994
33	As	2.211
34	Se	2.424
35	Br	2.685
36	Kr	2.966
37	Rb	0.706
38	Sr	0.963
39	Y	1.12
40	Zr	1.32
41	Nb	1.41
42	Mo	1.47
43	Tc	1.51
44	Ru	1.54
45	Rh	1.56
46	Pd	1.58
47	Ag	1.87
48	Cd	1.521
49	In	1.656
50	Sn	1.824
51	Sb	1.984
52	Te	2.158
53	I	2.359
54	Xe	2.582
55	Cs	0.659
56	Ba	0.881
71	Lu	1.09
72	Hf	1.16
73	Ta	1.34
74	W	1.47
75	Re	1.60
76	Os	1.65
77	Ir	1.68
78	Pt	1.72
79	Au	1.92
80	Hg	1.765
81	Tl	1.789
82	Pb	1.854
83	Bi	2.01
84	Po	2.19
85	At	2.39
86	Rn	2.60
87	Fr	0.67
88	Ra	0.89

References

WEL

As quoted at http://www.webelements.com/ from these sources:

A.L. Allred, J. Inorg. Nucl. Chem., 1961, 17, 215.
J.E. Huheey, E.A. Keiter, and R.L. Keiter in Inorganic Chemistry : Principles of Structure and Reactivity, 4th edition, HarperCollins, New York, USA, 1993.

CRC

As quoted from these sources in an online version of: David R. Lide (ed), CRC Handbook of Chemistry and Physics, 84th Edition. CRC Press. Boca Raton, Florida, 2003; Section 9, Molecular Structure and Spectroscopy; Electronegativity

Pauling, L., The Nature of the Chemical Bond, Third Edition, Cornell University Press, Ithaca, New York, 1960.
Allen, L.C., J. Am. Chem. Soc., 111, 9003, 1989.

LNG

As quoted from these sources in: J.A. Dean (ed), Lange's Handbook of Chemistry (15th Edition), McGraw-Hill, 1999; Section 4; Table 4.5, Electronegativities of the Elements.

L. Pauling, The Chemical Bond, Cornell University Press, Ithaca, New York, 1967.
L. C. Allen, J. Am. Chem. Soc. 111:9003 (1989).
A. L. Allred J. Inorg. Nucl. Chem. 17:215 (1961).

Allen Electronegativities

Three references are required to cover the values quoted in the table.

L. C. Allen, J. Am. Chem. Soc. 111:9003 (1989).
J. B. Mann, T. L. Meek and L. C. Allen, J. Am. Chem. Soc. 122:2780 (2000).
J. B. Mann, T. L. Meek, E. T. Knight, J. F. Capitani and L. C. Allen, J. Am. Chem. Soc. 122:5132 (2000).