Electronegativity - Overview, Factors, Elements, Applications, FAQs

Electronegativity - Overview, Factors, Elements, Applications, FAQs

Edited By Team Careers360 | Updated on Jul 02, 2025 04:31 PM IST

Electronegativity is another important concept within chemistry that provides insight into how the atomic structures of the different elements manage to attract some electrons when both of them are involved in a chemical bond. This idea was earlier formulated by Linus Pauling; electronegativity reflects how many electrons an element attracts toward its nucleus during the performance of a chemical bond. This property determines the characteristics of the bonding— it can be ionic, covalent, or polar covalent, and describes the distribution of charge within the atoms of the molecule. Since fluorine or oxygen has a higher electronegativity than the other elements, it attracts the electrons more sharply creating a strong polar covalent bond in which the electron is found more in the vicinity of fluorine or oxygen atom.

This Story also Contains
  1. Unveiling the Power of Electronegativity
  2. Some Solved Examples
  3. Conclusion
Electronegativity - Overview, Factors, Elements, Applications, FAQs
Electronegativity - Overview, Factors, Elements, Applications, FAQs

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This article delves into the concept of electronegativity, a crucial topic in the Class 11 Chemistry curriculum under the chapter "Classification of Elements and Periodic Table." Understanding electronegativity is essential not only for academic assessments but also for competitive examinations such as JEE Main, NEET, SRMJEE, BITSAT, WBJEE, BCECE, and others. Electronegativity plays a significant role in determining the nature of chemical bonds, influencing molecular polarity, and predicting the reactivity of substances. Given its importance, a thorough grasp of this concept is beneficial for students aiming to excel in these examinations.

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Unveiling the Power of Electronegativity

Electronegativity

The tendency of an atom to attract the shared pair of electrons towards itself is called electronegativity. It is a relative quantity. This concept was introduced in 1932 by Pauling. It has no units. Fluorine is the most electronegative element known so far and its value is arbitrarily assigned as 4.0. In moving from left to right in a period, the electronegativity increases while in moving from the top to bottom in a group, the electronegativity decreases.

Factors affecting Electronegativity

Several key influences determine an atom’s electronegativity:

First, as atomic size increases, electronegativity declines because outer electrons are farther from the nucleus and less strongly attracted .

Next, a higher effective nuclear charge—due to more protons or reduced shielding—boosts electronegativity by increasing the nucleus’s pull on valence electrons.

Lastly, an element’s oxidation state affects its electronegativity. Atoms in higher oxidation states have fewer electrons shielding the nucleus and a smaller radius, so they attract bonding electrons more strongly—as seen, for instance, with Fe³⁺ being more electronegative than Fe²⁺ .


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Recommended topic video on (Electronegativity)


Some Solved Examples


Example 1: The correct option concerning the Pauling electronegativity values of the elements is :

1) Ga < Ge

2) P > S

3) Si < Al

4) Te > Se

Solution: Electronegativity -A qualitative measure of the ability of an atom in a chemical compound to attract shared electrons is electronegativity.- wherein It is not a measurable quantity.

Electronegativity and non-metallic character -

Non-metallic elements have a strong tendency to gain electrons. Therefore electronegativity is directly related to non-metallic properties of elements.

- wherein

Electronegativity ∝ non-metallic property
Correct order
(1) Ga<Ge
(2) Si<Al
(3) P<S
(4) Te<Se

Hence, the answer is the option (1).

Example 2: The electronegativity of an element is related to ionization energy and

1) Atomic radii

2) Electron affinity

3) Ionic radii

4) Nucleus

Solution: The electronegativity depends upon the sum of Ionisation and Electron Affinity.

The electronegativity of any given element is not constant. It varies depending on the elements to which it is bound.

Though it is not measurable, it does provide a means to predict the nature of the force that holds atoms.

More electronegative elements will have positive Electron affinity due to electron attraction as well as more Ionisation Energy.

Hence, the answer is the option (2).

Example 3: Which of the following is the most electronegative?

1) Be

2) B

3) C

4) N

Solution: Electronegativity generally increases across a period from left to right.

e.g. from lithium to fluorine.

N is the most electronegative element among the given elements as we move from left to right in a period, the electronegativity increases.

Hence, the answer is the option (4).

Example 4: Which one of the following elements is most electronegative?

1) Fluorine

2) Sulphur

3) Oxygen

4) Bromine

Solution: As we learned, Variation of electronegativity along group

Electronegativity generally decreases down a group in the periodic table.

- wherein

e.g. from fluorine to astatine.

Electronegativity decreases as we move down the group and increases as we move from left to right in a period.

Hence, the answer is the option (1).

Example 5: Which of the following is most electronegative?

1) Carbon

2) Silicon

3) Lead

4) Tin

Solution: Electronegativity - The electronegativity of any element decreases down the group. Thus carbon is the most electronegative element.

Hence, the answer is the option (1).

Variation of Electronegativity

  • In moving from top to bottom in a group the atomic size increases thus the force of attraction decreases and hence the electronegativity decreases.

  • In moving from left to right in a period, the atomic size decreases and effective nuclear charge increases, thus the electronegativity increases.

  • Halogens are the most electronegative elements and fluorine has the highest electronegativity.

  • For transition elements, the electronegativity values vary between 1.1 to 1.3.

  • Metals have lower electronegativity values while non-metals have higher electronegativity values.

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Example 6: Two elements with electronegativities are 1.2 and 3.2 respectively, the bond formed between them will be:

1) Covalent

2) Metallic

3) Ionic

4) None

Solution: Electronegativity - Nature of Bond: The nature of the bond can be estimated from the electronegativity values of respective atoms.

(i) When the electronegativity difference between two atoms, i.e., MA—MB = 0, then the bond is purely covalent.

(ii) When MA - MB is small, the bond is polar but covalent.

(iii) When MA - MB is 1.9, the bond is 50% ionic and 50% covalent.

(iv) When MA—MB is greater than 1.9, the bond is more ionic and less covalent.

The percentage of ionic character is given by the following formula:

Percentage of ionic character = 16(MA - MB) + 3.5(MA - MB)2

MA and MB are the electronegativities of two bonded atoms, i.e., A and B.

The electronegativity difference between the constituent atoms must be greater than 1.9 to form the ionic bond.

Hence, the answer is the option (3).

Example 7: On going from right to left in a period in the periodic table the electronegativity of the elements
1) Increases

2) Decreases

3) Remain unchanged

4)Decreases first then increases

Solution: As we learned, Electronegativity is the ability of any atom to attract a bonded pair of electrons towards itself. It increases on moving from left to right along a period as the size of the atom decreases.

Hence, the answer is the option (1).

Practice more Questions from the link given below:


Importance of Electronegativity

The following predictions can be made out of the information on the electronegativities of atoms.

  • Nature of Element: The elements with lower electronegativity values are metals while the elements with higher electronegativity values are non-metals. The elements with intermediate electronegativity values are metalloids. Fluorine has the highest electronegativity value, thus it is the most non-metallic element. Similarly, cesium has the lowest electronegativity value, thus it is the most metallic element.

  • Nature of Oxides: The nature of the oxides formed by the elements can also be predicted by electronegativity. When the MO - MA difference is lower, then the oxide is acidic but when this difference MO - MA is large, then the oxide is basic. MO here is the electronegativity of oxygen.

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Conclusion

Electronegativity measures how strongly an atom attracts electrons in a chemical bond, directly influencing whether the bond is nonpolar, polar covalent, or ionic. Differences in electronegativity between atoms create charge separation—larger differences result in greater polarity and may even form ions . This polarity governs key chemical behaviors: polar molecules tend to dissolve in polar solvents (“like dissolves like”), exhibit higher boiling and melting points, and often engage in stronger intermolecular forces. Moreover, electronegativity affects acidity—atoms that strongly attract electrons stabilize negative charges in conjugate bases, enhancing acid strength. In short, electronegativity not only defines bond type and molecular polarity but also underpins solubility, thermal properties, and acid–base behavior.

Frequently Asked Questions (FAQs)

1. Why does electronegativity increase across a period?

Electronegativity increases across a period because number of charges on nucleus increases. As a result, the bonding pair of electrons is attracted more strongly.

2. What is the most electronegative atom/element?

Electronegativity of fluorine has the highest electronegativity.

3. Give electronegativity of Hydrogen, Carbon, Nitrogen and Oxygen?

Electronegativity of H is 2.20.

Electronegativity of C is 2.55.

Electronegativity of N is 3.04.

Electronegativity of O is 3.44.

4. As you move from top to bottom on periodic table, why does electronegativity decrease?

The atomic number increases as we proceed down the group. The nuclear charge increases as well, but the effect of the increase is mitigated by the addition of one shell. As a result, as we travel down the group, the value of electronegativity decreases.

5. Which of the following has highest electronegativity or arrange the following elements in the increasing order of electronegativity? C, N, Si, P.

Here we must find which element has the highest electronegativity for that in a group, electronegativity decreases as the size increases, leading to its ability to attract electrons decrease. Thus, P<N and Si<C.  In a period, as the size decreases, electronegativity increases due to the increase in effective nuclear charge.  Thus, C<N and P>Si. 

Hence, the overall order is Si<P<C<N Therefore, N has highest electronegative element.

6. What determines whether a bond is covalent, polar covalent, or ionic?

The greater the electronegativity difference between two atoms, the more electron density shifts toward the more electronegative atom. Small differences (<0.4) yield nonpolar covalent bonds, moderate differences produce polar covalent bonds, and large differences (>1.7–1.8) often lead to ionic character .

7. What factors influence an atom’s electronegativity?

Key influences include:

  • Atomic radius: smaller atoms hold electrons more tightly.

  • Effective nuclear charge: more protons increase the pull on electrons.

  • Electron shielding: inner-shell electrons can reduce the nucleus’s grabbing power

8. Is 1.7 electronegativity polar and non polar?

A ΔEN of 1.7 falls right on the threshold between highly polar covalent and ionic bonds. According to Pauling’s scale, such a difference implies about 50% ionic character, meaning the bond is neither fully ionic nor purely covalent. In most cases—especially between two nonmetals—this value is considered polar covalent, while bonds involving a metal may be classified as ionic 

9. What is electronegativity?
Electronegativity is the ability of an atom in a chemical bond to attract electrons towards itself. It measures how strongly an atom pulls shared electrons in a covalent bond.
10. Who introduced the concept of electronegativity?
The concept of electronegativity was introduced by Linus Pauling in 1932. He developed the first electronegativity scale, which is still widely used today.
11. How is electronegativity different from electron affinity?
Electronegativity measures an atom's ability to attract electrons in a chemical bond, while electron affinity is the energy released when an isolated atom in the gas phase accepts an electron. Electronegativity is a relative property, while electron affinity is an absolute measurement.
12. What are the main factors affecting electronegativity?
The main factors affecting electronegativity are:
13. How does atomic size affect electronegativity?
As atomic size decreases, electronegativity generally increases. This is because smaller atoms have their valence electrons closer to the nucleus, resulting in a stronger attraction to shared electrons in a bond.
14. What is the relationship between nuclear charge and electronegativity?
As the nuclear charge increases, electronegativity generally increases. A higher nuclear charge means a stronger attraction between the nucleus and the valence electrons, leading to a greater ability to attract shared electrons in a bond.
15. How does the shielding effect influence electronegativity?
The shielding effect decreases electronegativity. Inner electron shells shield the valence electrons from the full nuclear charge, reducing the atom's ability to attract shared electrons. Less shielding results in higher electronegativity.
16. Why does electronegativity generally increase across a period in the periodic table?
Electronegativity increases across a period because atomic size decreases while nuclear charge increases. The valence electrons are held more tightly, increasing the atom's ability to attract shared electrons in a bond.
17. How does electronegativity change down a group in the periodic table?
Electronegativity generally decreases down a group because atomic size increases, and the valence electrons are farther from the nucleus. This results in a weaker attraction to shared electrons in a bond.
18. Which element has the highest electronegativity?
Fluorine (F) has the highest electronegativity of all elements, with a value of 3.98 on the Pauling scale. This is due to its small atomic size and high nuclear charge relative to its valence electrons.
19. Why does noble gases have no electronegativity value?
Noble gases have no electronegativity value because they have a full outer electron shell and do not typically form chemical bonds. Electronegativity is a property related to an atom's ability to attract electrons in a bond, which noble gases rarely do.
20. How is electronegativity measured?
Electronegativity is not directly measurable but is calculated using various methods. The most common scales are the Pauling scale, the Mulliken scale, and the Allred-Rochow scale. These scales use different approaches but generally produce similar relative values.
21. What is the Pauling scale of electronegativity?
The Pauling scale is the most widely used electronegativity scale. It assigns values from 0.7 (francium) to 4.0 (fluorine) based on bond dissociation energies. The scale is dimensionless and provides relative values for comparing elements.
22. How does electronegativity affect bond polarity?
Electronegativity differences between bonded atoms determine bond polarity. A larger difference in electronegativity results in a more polar bond, with electrons being pulled more strongly towards the more electronegative atom.
23. What is the relationship between electronegativity and ionization energy?
Electronegativity and ionization energy generally show a positive correlation. Elements with high electronegativity tend to have high ionization energies because both properties relate to an atom's ability to attract or hold onto electrons.
24. How does electronegativity influence the acidity of compounds?
Higher electronegativity of atoms bonded to hydrogen increases the acidity of a compound. More electronegative atoms pull electron density away from the H atom, making it easier to lose as a proton (H+) in solution.
25. What role does electronegativity play in determining oxidation states?
Electronegativity helps determine oxidation states in compounds. The more electronegative element in a bond is assigned the negative oxidation state, while the less electronegative element takes the positive oxidation state.
26. How does electronegativity affect the strength of hydrogen bonds?
Higher electronegativity of atoms involved in hydrogen bonding leads to stronger hydrogen bonds. This is because more electronegative atoms create a greater partial negative charge, strengthening the attraction to the partially positive hydrogen.
27. Why do transition metals have lower electronegativity values compared to main group elements?
Transition metals generally have lower electronegativity values because they have larger atomic sizes and more shielding from their d-orbitals. This results in a weaker attraction to shared electrons in chemical bonds.
28. How does electronegativity influence the nature of chemical bonds?
Electronegativity differences determine the nature of chemical bonds. Small differences lead to covalent bonds, larger differences result in polar covalent bonds, and very large differences produce ionic bonds.
29. What is the electronegativity trend in the halogens?
Electronegativity decreases down the halogen group (F > Cl > Br > I > At). This trend is due to increasing atomic size and decreasing effective nuclear charge as we move down the group.
30. How does electronegativity affect the reactivity of elements?
Elements with high electronegativity tend to be more reactive as non-metals, readily accepting electrons to form anions. Elements with low electronegativity are more reactive as metals, easily losing electrons to form cations.
31. What is the significance of electronegativity in organic chemistry?
In organic chemistry, electronegativity helps predict:
32. How does electronegativity influence the boiling and melting points of compounds?
Compounds with larger electronegativity differences between atoms tend to have higher boiling and melting points. This is due to stronger intermolecular forces resulting from greater bond polarity.
33. What is the relationship between electronegativity and electron affinity?
Electronegativity and electron affinity generally show a positive correlation. Elements with high electronegativity often have high electron affinities, as both properties relate to an atom's tendency to attract electrons.
34. How does electronegativity affect the solubility of compounds?
Compounds with large electronegativity differences between atoms tend to be more soluble in polar solvents like water. This is because the resulting bond polarity increases the compound's overall polarity, enhancing its interaction with polar solvent molecules.
35. What is the concept of electronegativity equalization?
Electronegativity equalization is the principle that when atoms form a chemical bond, they tend to adjust their electron distributions to equalize their electronegativities. This results in a more stable bonding arrangement.
36. How does electronegativity influence the strength of covalent bonds?
Moderate differences in electronegativity generally lead to stronger covalent bonds. This is because some charge separation enhances electrostatic attraction between atoms. However, very large differences can lead to ionic bonding instead.
37. What is the relationship between electronegativity and metallic character?
Electronegativity and metallic character have an inverse relationship. Elements with low electronegativity tend to have high metallic character, as they easily lose electrons to form metallic bonds.
38. How does electronegativity affect the color of transition metal complexes?
Electronegativity of ligands in transition metal complexes affects the crystal field splitting, which determines the energy of d-orbital transitions. This, in turn, influences the wavelengths of light absorbed and thus the observed color of the complex.
39. What is the role of electronegativity in determining the shape of molecules?
While electronegativity doesn't directly determine molecular shape, it influences bond polarity, which can affect electron pair repulsions. This can lead to slight deviations from ideal VSEPR (Valence Shell Electron Pair Repulsion) geometries.
40. How does electronegativity influence the strength of intermolecular forces?
Higher electronegativity differences in molecules lead to stronger dipole-dipole interactions and hydrogen bonding. This results in stronger intermolecular forces and affects properties like boiling point and solubility.
41. What is the concept of group electronegativity?
Group electronegativity refers to the collective electronegativity of a group of atoms in a molecule. It's useful for predicting the behavior of functional groups in organic chemistry and understanding substituent effects.
42. How does electronegativity affect the stability of free radicals?
More electronegative atoms or groups can stabilize free radicals by delocalizing the unpaired electron through inductive or resonance effects. This makes the radical more stable and less reactive.
43. What is the relationship between electronegativity and electron density?
Higher electronegativity atoms attract more electron density in a chemical bond. This results in an uneven distribution of electron density, with a higher concentration around the more electronegative atom.
44. How does electronegativity influence the strength of acids and bases?
Higher electronegativity of atoms bonded to a proton (H+) increases acid strength by making it easier to lose the proton. For bases, lower electronegativity of the electron-donating atom generally increases base strength.
45. What is the concept of absolute electronegativity?
Absolute electronegativity is defined as the average of the ionization energy and electron affinity of an atom. It provides a more fundamental basis for electronegativity calculations than relative scales like Pauling's.
46. How does electronegativity affect the polarizability of atoms and molecules?
Generally, atoms with lower electronegativity are more polarizable. This is because their electrons are held less tightly and can be more easily distorted by external electric fields.
47. What is the role of electronegativity in determining the nature of oxides?
The electronegativity of elements determines whether their oxides are acidic, basic, or amphoteric. Highly electronegative elements form acidic oxides, while less electronegative elements form basic oxides.
48. How does electronegativity influence the strength of coordination bonds in complexes?
More electronegative ligands generally form stronger coordination bonds with metal ions. This is due to their greater ability to attract electron density from the metal, resulting in stronger electrostatic interactions.
49. What is the concept of electronegativity inversion?
Electronegativity inversion occurs when an atom or group that is typically less electronegative becomes more electronegative due to its chemical environment. This can happen in certain compounds or under specific conditions.
50. How does electronegativity affect the reactivity of carbonyl compounds?
Higher electronegativity of substituents attached to the carbonyl carbon increases its electrophilicity. This makes the carbonyl group more reactive towards nucleophilic addition reactions.
51. What is the relationship between electronegativity and electron-withdrawing ability?
Electronegativity and electron-withdrawing ability are closely related. More electronegative atoms or groups are generally stronger electron-withdrawing groups, as they attract electron density more strongly.
52. How does electronegativity influence the strength of sigma and pi bonds?
Electronegativity differences affect both sigma and pi bonds. For sigma bonds, moderate differences can strengthen the bond. For pi bonds, large differences can weaken the bond by reducing electron delocalization.
53. What is the role of electronegativity in determining the properties of intermetallic compounds?
Electronegativity differences between metals in intermetallic compounds influence their bonding character, ranging from metallic to partially ionic. This affects properties such as melting point, hardness, and electrical conductivity.
54. How does electronegativity affect the magnetic properties of transition metal complexes?
The electronegativity of ligands in transition metal complexes influences the crystal field splitting, which determines the electron configuration of the metal ion. This, in turn, affects the complex's magnetic properties (paramagnetic or diamagnetic).
55. What is the concept of group shift in electronegativity?
Group shift refers to the change in electronegativity of an atom when it's part of a functional group. The collective effect of the group can make an atom more or less electronegative than it would be in isolation.
56. How does electronegativity influence the strength of metal-metal bonds?
Electronegativity differences between metals affect the nature and strength of metal-metal bonds. Smaller differences generally lead to stronger, more covalent metal-metal bonds, while larger differences result in more polar or even ionic interactions.
57. What is the role of electronegativity in determining the properties of semiconductor materials?
Electronegativity differences between elements in semiconductor compounds influence their band structure, affecting properties like band gap, carrier mobility, and conductivity. This is crucial in designing materials for electronic applications.
58. How does electronegativity affect the catalytic activity of transition metals?
The electronegativity of transition metals influences their ability to form bonds with reactants and intermediates in catalytic processes. It affects the metal's electron-donating and accepting properties, which are crucial for catalytic activity.

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