Electronegativities of the elements (data page)

Electronegativity (Pauling scale)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Group →
↓ Period
1 H
2.20
He
 
2 Li
0.98
Be
1.57
B
2.04
C
2.55
N
3.04
O
3.44
F
3.98
Ne
 
3 Na
0.93
Mg
1.31
Al
1.61
Si
1.90
P
2.19
S
2.58
Cl
3.16
Ar
 
4 K
0.82
Ca
1.00
Sc
1.36
Ti
1.54
V
1.63
Cr
1.66
Mn
1.55
Fe
1.83
Co
1.88
Ni
1.91
Cu
1.90
Zn
1.65
Ga
1.81
Ge
2.01
As
2.18
Se
2.55
Br
2.96
Kr
3.00
5 Rb
0.82
Sr
0.95
Y
1.22
Zr
1.33
Nb
1.6
Mo
2.16
Tc
1.9
Ru
2.2
Rh
2.28
Pd
2.20
Ag
1.93
Cd
1.69
In
1.78
Sn
1.96
Sb
2.05
Te
2.1
I
2.66
Xe
2.60
6 Cs
0.79
Ba
0.89
La
1.1
1 asterisk Hf
1.3
Ta
1.5
W
2.36
Re
1.9
Os
2.2
Ir
2.20
Pt
2.28
Au
2.54
Hg
2.00
Tl
1.62
Pb
1.87
Bi
2.02
Po
2.0
At
2.2
Rn
2.2
7 Fr
>0.79[en 1]
Ra
0.9
Ac
1.1
1 asterisk Rf
 
Db
 
Sg
 
Bh
 
Hs
 
Mt
 
Ds
 
Rg
 
Cn
 
Nh
 
Fl
 
Mc
 
Lv
 
Ts
 
Og
 

1 asterisk Ce
1.12
Pr
1.13
Nd
1.14
Pm
1.13
Sm
1.17
Eu
1.2
Gd
1.2
Tb
1.1
Dy
1.22
Ho
1.23
Er
1.24
Tm
1.25
Yb
1.1
Lu
1.27
1 asterisk Th
1.3
Pa
1.5
U
1.38
Np
1.36
Pu
1.28
Am
1.13
Cm
1.28
Bk
1.3
Cf
1.3
Es
1.3
Fm
1.3
Md
1.3
No
1.3
Lr
1.3[en 2]

Values are given for the elements in their most common and stable oxidation states.
See also: Electronegativities of the elements (data page)

  1. ^ The electronegativity of francium was chosen by Pauling as 0.7, close to that of caesium (also assessed 0.7 at that point). The base value of hydrogen was later increased by 0.10 and caesium's electronegativity was later refined to 0.79; however, no refinements have been made for francium as no experiment has been conducted. However, francium is expected and, to a small extent, observed to be more electronegative than caesium. See francium for details.
  2. ^ See Brown, Geoffrey (2012). The Inaccessible Earth: An integrated view to its structure and composition. Springer Science & Business Media. p. 88. ISBN 9789401115162.
Number Symbol Name use WEL CRC LNG
1 H hydrogen 2.20 same
2 He helium no data same
3 Li lithium 0.98 same
4 Be beryllium 1.57 same
5 B boron 2.04 same
6 C carbon 2.55 same
7 N nitrogen 3.04 same
8 O oxygen 3.44 same
9 F fluorine 3.98 3.98 3.98 3.90
10 Ne neon no data same
11 Na sodium 0.93 same
12 Mg magnesium 1.31 same
13 Al aluminium 1.61 same
14 Si silicon 1.90 same
15 P phosphorus 2.19 same
16 S sulfur 2.58 same
17 Cl chlorine 3.16 same
18 Ar argon no data same
19 K potassium 0.82 same
20 Ca calcium 1.00 same
21 Sc scandium 1.36 same
22 Ti titanium 1.54 same
23 V vanadium 1.63 same
24 Cr chromium 1.66 same
25 Mn manganese 1.55 same
26 Fe iron 1.83 same
27 Co cobalt 1.88 same
28 Ni nickel 1.91 same
29 Cu copper 1.90 same
30 Zn zinc 1.65 same
31 Ga gallium 1.81 same
32 Ge germanium 2.01 same
33 As arsenic 2.18 same
34 Se selenium 2.55 same
35 Br bromine 2.96 same
36 Kr krypton 3.00 3.00 no data no data
37 Rb rubidium 0.82 same
38 Sr strontium 0.95 same
39 Y yttrium 1.22 same
40 Zr zirconium 1.33 same
41 Nb niobium 1.6 same
42 Mo molybdenum 2.16 same
43 Tc technetium 1.9 1.9 2.10 2.10
44 Ru ruthenium 2.2 same
45 Rh rhodium 2.28 same
46 Pd palladium 2.20 same
47 Ag silver 1.93 same
48 Cd cadmium 1.69 same
49 In indium 1.78 same
50 Sn tin 1.96 same
51 Sb antimony 2.05 same
52 Te tellurium 2.1 same
53 I iodine 2.66 same
54 Xe xenon 2.6 2.6 2.60 no data
55 Cs caesium 0.79 same
56 Ba barium 0.89 same
57 La lanthanum 1.10 same
58 Ce cerium 1.12 same
59 Pr praseodymium 1.13 same
60 Nd neodymium 1.14 same
61 Pm promethium no data same
62 Sm samarium 1.17 same
63 Eu europium no data same
64 Gd gadolinium 1.20 same
65 Tb terbium no data same
66 Dy dysprosium 1.22 same
67 Ho holmium 1.23 same
68 Er erbium 1.24 same
69 Tm thulium 1.25 same
70 Yb ytterbium no data same
71 Lu lutetium 1.27 1.27 1.0 1.0
72 Hf hafnium 1.3 same
73 Ta tantalum 1.5 same
74 W tungsten 2.36 2.36 1.7 1.7
75 Re rhenium 1.9 same
76 Os osmium 2.2 same
77 Ir iridium 2.20 2.20 2.2 2.2
78 Pt platinum 2.28 2.28 2.2 2.2
79 Au gold 2.54 2.54 2.4 2.4
80 Hg mercury 2.00 2.00 1.9 1.9
81 Tl thallium 1.62 1.62 1.8 1.8
82 Pb lead 2.33 2.33 1.8 1.8
83 Bi bismuth 2.02 2.02 1.9 1.9
84 Po polonium 2.0 same
85 At astatine 2.2 same
86 Rn radon no data same
87 Fr francium no data 0.7
88 Ra radium 0.9 same
89 Ac actinium 1.1 same
90 Th thorium 1.3 same
91 Pa protactinium 1.5 same
92 U uranium 1.38 1.38 1.7 1.7
93 Np neptunium 1.36 1.36 1.3 1.3
94 Pu plutonium 1.28 1.28 1.3 1.3
95 Am americium 1.3 1.3 no data 1.3
96 Cm curium 1.3 1.3 no data 1.3
97 Bk berkelium 1.3 1.3 no data 1.3
98 Cf californium 1.3 1.3 no data 1.3
99 Es einsteinium 1.3 1.3 no data 1.3
100 Fm fermium 1.3 1.3 no data 1.3
101 Md mendelevium 1.3 1.3 no data 1.3
102 No nobelium 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)

Electronegativity using the Allen scale
Group → 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
↓ Period
1 H
2.300
He
4.160
2 Li
0.912
Be
1.576
B
2.051
C
2.544
N
3.066
O
3.610
F
4.193
Ne
4.787
3 Na
0.869
Mg
1.293
Al
1.613
Si
1.916
P
2.253
S
2.589
Cl
2.869
Ar
3.242
4 K
0.734
Ca
1.034
Sc
1.19
Ti
1.38
V
1.53
Cr
1.65
Mn
1.75
Fe
1.80
Co
1.84
Ni
1.88
Cu
1.85
Zn
1.59
Ga
1.756
Ge
1.994
As
2.211
Se
2.424
Br
2.685
Kr
2.966
5 Rb
0.706
Sr
0.963
Y
1.12
Zr
1.32
Nb
1.41
Mo
1.47
Tc
1.51
Ru
1.54
Rh
1.56
Pd
1.58
Ag
1.87
Cd
1.52
In
1.656
Sn
1.824
Sb
1.984
Te
2.158
I
2.359
Xe
2.582
6 Cs
0.659
Ba
0.881
Lu
1.09
Hf
1.16
Ta
1.34
W
1.47
Re
1.60
Os
1.65
Ir
1.68
Pt
1.72
Au
1.92
Hg
1.76
Tl
1.789
Pb
1.854
Bi
2.01
Po
2.19
At
2.39
Rn
2.60
7 Fr
0.67
Ra
0.89
See also: Electronegativities of the elements (data page)
Number Symbol Name Electronegativity
1 H hydrogen 2.300
2 He helium 4.160
3 Li lithium 0.912
4 Be beryllium 1.576
5 B boron 2.051
6 C carbon 2.544
7 N nitrogen 3.066
8 O oxygen 3.610
9 F fluorine 4.193
10 Ne neon 4.787
11 Na sodium 0.869
12 Mg magnesium 1.293
13 Al aluminium 1.613
14 Si silicon 1.916
15 P phosphorus 2.253
16 S sulfur 2.589
17 Cl chlorine 2.869
18 Ar argon 3.242
19 K potassium 0.734
20 Ca calcium 1.034
21 Sc scandium 1.19
22 Ti titanium 1.38
23 V vanadium 1.53
24 Cr chromium 1.65
25 Mn manganese 1.75
26 Fe iron 1.80
27 Co cobalt 1.84
28 Ni nickel 1.88
29 Cu copper 1.85
30 Zn zinc 1.59
31 Ga gallium 1.756
32 Ge germanium 1.994
33 As arsenic 2.211
34 Se selenium 2.424
35 Br bromine 2.685
36 Kr krypton 2.966
37 Rb rubidium 0.706
38 Sr strontium 0.963
39 Y yttrium 1.12
40 Zr zirconium 1.32
41 Nb niobium 1.41
42 Mo molybdenum 1.47
43 Tc technetium 1.51
44 Ru ruthenium 1.54
45 Rh rhodium 1.56
46 Pd palladium 1.58
47 Ag silver 1.87
48 Cd cadmium 1.52
49 In indium 1.656
50 Sn tin 1.824
51 Sb antimony 1.984
52 Te tellurium 2.158
53 I iodine 2.359
54 Xe xenon 2.582
55 Cs caesium 0.659
56 Ba barium 0.881
71 Lu lutetium 1.09
72 Hf hafnium 1.16
73 Ta tantalum 1.34
74 W tungsten 1.47
75 Re rhenium 1.60
76 Os osmium 1.65
77 Ir iridium 1.68
78 Pt platinum 1.72
79 Au gold 1.92
80 Hg mercury 1.76
81 Tl thallium 1.789
82 Pb lead 1.854
83 Bi bismuth 2.01
84 Po polonium 2.19
85 At astatine 2.39
86 Rn radon 2.60
87 Fr francium 0.67
88 Ra radium 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).
Chemical polarity

In chemistry, polarity is a separation of electric charge leading to a molecule or its chemical groups having an electric dipole moment, with a negatively charged end and a positively charged end.

Polar molecules must contain polar bonds due to a difference in electronegativity between the bonded atoms. A polar molecule with two or more polar bonds must have a geometry which is asymmetric in at least one direction, so that the bond dipoles do not cancel each other.

Polar molecules interact through dipole–dipole intermolecular forces and hydrogen bonds. Polarity underlies a number of physical properties including surface tension, solubility, and melting and boiling points.

Electronegativity

Electronegativity, symbol χ, is a chemical property that describes the tendency of an atom to attract a shared pair of electrons (or electron density) towards itself. An atom's electronegativity is affected by both its atomic number and the distance at which its valence electrons reside from the charged nucleus. The higher the associated electronegativity number, the more an atom or a substituent group attracts electrons towards itself.

On the most basic level, electronegativity is determined by factors like the nuclear charge (the more protons an atom has, the more "pull" it will have on electrons) and the number/location of other electrons present in the atomic shells (the more electrons an atom has, the farther from the nucleus the valence electrons will be, and as a result the less positive charge they will experience—both because of their increased distance from the nucleus, and because the other electrons in the lower energy core orbitals will act to shield the valence electrons from the positively charged nucleus).

The opposite of electronegativity is electropositivity: a measure of an element's ability to donate electrons.

The term "electronegativity" was introduced by Jöns Jacob Berzelius in 1811,

though the concept was known even before that and was studied by many chemists including Avogadro.

In spite of its long history, an accurate scale of electronegativity was not developed until 1932, when Linus Pauling proposed an electronegativity scale, which depends on bond energies, as a development of valence bond theory. It has been shown to correlate with a number of other chemical properties. Electronegativity cannot be directly measured and must be calculated from other atomic or molecular properties. Several methods of calculation have been proposed, and although there may be small differences in the numerical values of the electronegativity, all methods show the same periodic trends between elements.

The most commonly used method of calculation is that originally proposed by Linus Pauling. This gives a dimensionless quantity, commonly referred to as the Pauling scale (χr), on a relative scale running from 0.79 to 3.98 (hydrogen = 2.20). When other methods of calculation are used, it is conventional (although not obligatory) to quote the results on a scale that covers the same range of numerical values: this is known as an electronegativity in Pauling units.

As it is usually calculated, electronegativity is not a property of an atom alone, but rather a property of an atom in a molecule. Properties of a free atom include ionization energy and electron affinity. It is to be expected that the electronegativity of an element will vary with its chemical environment, but it is usually considered to be a transferable property, that is to say that similar values will be valid in a variety of situations.

Caesium is the least electronegative element in the periodic table (=0.79), while fluorine is most electronegative (=3.98). Francium and caesium were originally both assigned 0.7; caesium's value was later refined to 0.79, but no experimental data allows a similar refinement for francium. However, francium's ionization energy is known to be slightly higher than caesium's, in accordance with the relativistic stabilization of the 7s orbital, and this in turn implies that francium is in fact more electronegative than caesium.

List of data references for chemical elements

Values for many properties of the elements, together with various references, are collected on these data pages.

Outline of chemistry

The following outline is provided as an overview of and topical guide to chemistry:

Chemistry – science of atomic matter (matter that is composed of chemical elements), especially its chemical reactions, but also including its properties, structure, composition, behavior, and changes as they relate the chemical reactions. Chemistry is centrally concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds.

Oxidation state

The oxidation state, sometimes referred to as oxidation number, describes the degree of oxidation (loss of electrons) of an atom in a chemical compound. Conceptually, the oxidation state, which may be positive, negative or zero, is the hypothetical charge that an atom would have if all bonds to atoms of different elements were 100% ionic, with no covalent component. This is never exactly true for real bonds.

The term oxidation was first used by Antoine Lavoisier to signify reaction of a substance with oxygen. Much later, it was realized that the substance, upon being oxidized, loses electrons, and the meaning was extended to include other reactions in which electrons are lost, regardless of whether oxygen was involved.

Oxidation states are typically represented by integers which may be positive, zero, or negative. In some cases, the average oxidation state of an element is a fraction, such as 8/3 for iron in magnetite (Fe3O4). The highest known oxidation state is reported to be +9 in the tetroxoiridium(IX) cation (IrO+4). It is predicted that even a +10 oxidation state may be achievable by platinum in the tetroxoplatinum(X) cation (PtO2+4). The lowest oxidation state is −4, as for carbon in methane or for chromium in [Cr(CO)4]4−.

The increase in oxidation state of an atom, through a chemical reaction, is known as an oxidation; a decrease in oxidation state is known as a reduction. Such reactions involve the formal transfer of electrons: a net gain in electrons being a reduction, and a net loss of electrons being an oxidation. For pure elements, the oxidation state is zero.

The oxidation state of an atom does not represent the "real" charge on that atom, or any other actual atomic property. This is particularly true of high oxidation states, where the ionization energy required to produce a multiply positive ion is far greater than the energies available in chemical reactions. Additionally, oxidation states of atoms in a given compound may vary depending on the choice of electronegativity scale used in their calculation. Thus, the oxidation state of an atom in a compound is purely a formalism. It is nevertheless important in understanding the nomenclature conventions of inorganic compounds. Also, a number of observations pertaining to chemical reactions may be explained at a basic level in terms of oxidation states.

In inorganic nomenclature, the oxidation state is represented by a Roman numeral placed after the element name inside a parenthesis or as a superscript after the element symbol.

Robert Thomas Sanderson

Robert Thomas Sanderson (1912–1989) was an American inorganic chemist, more commonly known by the initials "R.T." found in his papers. He received his Ph.D. degree from the University of Chicago for his research in boron chemistry. After working in Texaco's research lab, he became a professor and spent his career on the faculties of the University of Florida, the University of Iowa, and Arizona State University. He also created a company supplying safety posters and lab-related artwork of his own design, and published several books including Vacuum Manipulation of Volatile Compounds.

Elements
Data
Periodic table forms
Sets of elements
Elements
History
See also

This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.