Which element has the highest Electronegativity in the periodic table?

📚 Chapter: Classification of Elements and Periodicity in Properties

📘 Answer

🏆 Fluorine (F)

Fluorine (F) is the most electronegative element in the periodic table.

Its electronegativity on the Pauling scale is approximately 3.98, the highest value of all elements.

🔍 Why does Fluorine have the highest electronegativity?

• Fluorine has a very small atomic radius.
• It has a relatively high effective nuclear charge.
• Its valence shell is close to the nucleus.
• Therefore, it strongly attracts the shared electron pair in a chemical bond.

Small Atomic Radius + High Effective Nuclear Charge
↓
Strong Attraction for Shared Electrons
↓
Highest Electronegativity

📊 Important Comparison

Element	Approx. Pauling Electronegativity
F	3.98
O	3.44
Cl	3.16
N	3.04

✅ Final Answer

Fluorine (F)

Fluorine has the highest electronegativity in the periodic table, with a Pauling electronegativity of approximately 3.98.

20 MCQs with Answers

1. Which element has the highest electronegativity?

A) Oxygen

B) Chlorine

C) Fluorine

D) Nitrogen

✅ Answer

C) Fluorine

---

2. The electronegativity of fluorine on the Pauling scale is approximately:

A) 2.20

B) 3.00

C) 3.44

D) 3.98

✅ Answer

D) 3.98

---

3. Fluorine belongs to which group?

A) 1

B) 15

C) 17

D) 18

✅ Answer

C) 17

---

4. Fluorine has high electronegativity mainly because of:

A) Large atomic radius

B) Small atomic radius

C) Low nuclear charge

D) Many electron shells

✅ Answer

B) Small atomic radius

---

5. Which element is more electronegative than chlorine?

A) Fluorine

B) Bromine

C) Iodine

D) Sulfur

✅ Answer

A) Fluorine

---

6. Electronegativity generally increases:

A) Down a group

B) From right to left

C) From left to right across a period

D) Randomly

✅ Answer

C

---

7. Fluorine is a member of the:

A) Alkali metals

B) Alkaline earth metals

C) Halogens

D) Noble gases

✅ Answer

C) Halogens

---

8. Which property of fluorine contributes to its high electronegativity?

A) Small atomic size

B) Large number of shells

C) Low effective nuclear charge

D) Metallic character

✅ Answer

A) Small atomic size

---

9. Which has the greatest attraction for a shared electron pair?

A) Li

B) C

C) O

D) F

✅ Answer

D) F

---

10. The highest electronegativity is found toward the:

A) Bottom-left

B) Top-right

C) Centre

D) Bottom-centre

✅ Answer

B) Top-right

---

11. Which is the most electronegative halogen?

A) Cl

B) Br

C) I

D) F

✅ Answer

D) F

---

12. Which element has electronegativity approximately 3.44?

A) F

B) O

C) N

D) Cl

✅ Answer

B) O

---

13. The small atomic radius of fluorine results in:

A) Weak attraction for bonding electrons

B) Strong attraction for bonding electrons

C) Low electronegativity

D) High metallic character

✅ Answer

B

---

14. Fluorine has how many valence electrons?

A) 5

B) 6

C) 7

D) 8

✅ Answer

C) 7

---

15. Fluorine belongs to which block?

A) s-block

B) p-block

C) d-block

D) f-block

✅ Answer

B) p-block

---

16. Which element has higher electronegativity?

A) F

B) Cl

C) Both equal

D) I

✅ Answer

A) F

---

17. Electronegativity measures the ability of an atom to:

A) Attract shared electrons

B) Lose neutrons

C) Attract protons

D) Lose its nucleus

✅ Answer

A

---

18. Which element has the strongest non-metallic character among the following?

A) Na

B) Mg

C) Cl

D) K

✅ Answer

C) Cl

---

19. Fluorine's high electronegativity is associated with:

A) High effective nuclear charge

B) Very large atomic radius

C) Many occupied shells

D) Low nuclear attraction

✅ Answer

A

---

20. The correct statement is:

A) Fluorine has the lowest electronegativity

B) Fluorine has the highest electronegativity

C) Chlorine is more electronegative than fluorine

D) Electronegativity is absent in fluorine

✅ Answer

B) Fluorine has the highest electronegativity

Q. Which element has the highest electronegativity in the periodic table?

Solution: Fluorine (F) has the highest electronegativity in the periodic table. Its Pauling electronegativity is approximately 3.98.

Q. Why does fluorine have the highest electronegativity?

Solution:

• Fluorine has a very small atomic radius.
• It has a high effective nuclear charge.
• Therefore, it strongly attracts the shared electron pair towards itself.

Q. Explain the reasons for the highest electronegativity of fluorine.

Solution: Fluorine has the smallest atomic radius among the halogens and a high effective nuclear charge. Its valence electrons are close to the nucleus. Hence, the attraction between the nucleus and the shared pair of bonding electrons is very strong. Therefore, fluorine has the highest electronegativity, approximately 3.98 on the Pauling scale.

Q. Discuss the position of fluorine in the periodic trend of electronegativity.

Solution:

Electronegativity generally increases from left to right across a period and decreases down a group. Fluorine is located in Group 17 and Period 2. It has a very small atomic size and high effective nuclear charge.

Because its valence shell is very close to the nucleus, fluorine strongly attracts the shared pair of electrons in a covalent bond. Hence, it has the highest electronegativity of all elements.

Fluorine (F) → Highest Electronegativity → ≈ 3.98 (Pauling scale)

Q. Explain in detail why fluorine has the highest electronegativity in the periodic table.

1. Small Atomic Size

Fluorine is a second-period element and has only two occupied electron shells. Its atomic radius is therefore very small.

2. High Effective Nuclear Charge

Fluorine has nine protons, while its inner-shell electrons provide relatively limited shielding. Thus its valence electrons experience a strong effective nuclear attraction.

3. Strong Attraction for Bonding Electrons

Because the valence shell is close to the nucleus, fluorine strongly attracts the shared electron pair in a covalent bond.

4. Periodic Trend

Electronegativity generally increases across a period and decreases down a group. Fluorine is at the upper-right side of the periodic table (excluding noble gases), where electronegativity is highest.

Small Atomic Radius
+
High Effective Nuclear Charge
↓
Strong Attraction for Shared Electrons
↓
Highest Electronegativity: F

Final Answer:
Fluorine (F) is the most electronegative element in the periodic table. Its Pauling electronegativity is approximately 3.98.

🎯 Quick Revision

Highest Electronegativity: Fluorine (F)
Group: 17
Period: 2
Block: p-block
Pauling value: ≈ 3.98
Main reason: Small atomic radius + high effective nuclear charge

What is the relation between Electronegativity and Non-metallic character?

📚 Chapter: Classification of Elements and Periodicity in Properties

📘 Answer

Electronegativity and non-metallic character are directly related. An element having higher electronegativity generally shows a stronger non-metallic character.

Electronegativity ↑   →   Non-metallic Character ↑

Non-metals have a strong tendency to attract electrons towards themselves. Therefore, elements with high electronegativity are generally more non-metallic in nature.

🔍 Periodic Trend

Across a period:

Electronegativity generally increases from left to right, and therefore non-metallic character also increases.

Metallic Character ↓   |   Non-metallic Character ↑

Left → Right

Down a group:

Electronegativity generally decreases down a group, so non-metallic character decreases and metallic character increases.

📊 Example

In the second period:

Li → Be → B → C → N → O → F

Non-metallic character generally ↑
Electronegativity generally ↑

Fluorine has the highest electronegativity and is strongly non-metallic, whereas lithium is much more metallic and has much lower electronegativity.

✅ Final Answer

Higher electronegativity indicates a greater tendency to attract electrons and is generally associated with stronger non-metallic character.

Electronegativity ↑ → Non-metallic Character ↑

20 MCQs with Answers

1. Electronegativity and non-metallic character are generally:

A) Directly related

B) Inversely related

C) Unrelated

D) Always equal

✅ Answer

A) Directly related

---

2. An element with high electronegativity generally has:

A) High metallic character

B) High non-metallic character

C) Zero non-metallic character

D) No chemical activity

✅ Answer

B) High non-metallic character

---

3. Across a period, non-metallic character generally:

A) Decreases

B) Increases

C) Remains constant

D) Becomes zero

✅ Answer

B) Increases

---

4. Across a period, electronegativity generally:

A) Increases

B) Decreases

C) Remains constant

D) Has no trend

✅ Answer

A) Increases

---

5. Which element is strongly non-metallic?

A) Na

B) Mg

C) F

D) K

✅ Answer

C) F

---

6. Fluorine has a strong non-metallic character because it has:

A) Low electronegativity

B) High electronegativity

C) Large atomic size

D) Low nuclear charge

✅ Answer

B) High electronegativity

---

7. Down a group, non-metallic character generally:

A) Increases

B) Decreases

C) Remains constant

D) Doubles

✅ Answer

B) Decreases

---

8. Down a group, metallic character generally:

A) Increases

B) Decreases

C) Remains zero

D) Does not change

✅ Answer

A) Increases

---

9. Which property is generally associated with non-metals?

A) Low electronegativity

B) High electronegativity

C) Very large atomic size only

D) Easy loss of electrons

✅ Answer

B) High electronegativity

---

10. Which has greater non-metallic character?

A) Li

B) F

C) Na

D) K

✅ Answer

B) F

---

11. The tendency of an atom to attract shared electrons is called:

A) Ionization enthalpy

B) Electronegativity

C) Electron affinity

D) Atomic radius

✅ Answer

B) Electronegativity

---

12. Which trend is correct across a period?

A) Metallic character ↑, non-metallic character ↓

B) Metallic character ↓, non-metallic character ↑

C) Both decrease

D) Both remain constant

✅ Answer

B

---

13. High electronegativity means a stronger tendency to:

A) Lose shared electrons

B) Attract shared electrons

C) Lose protons

D) Lose neutrons

✅ Answer

B) Attract shared electrons

---

14. Which element is more non-metallic?

A) Na

B) Cl

C) Mg

D) Al

✅ Answer

B) Cl

---

15. The most electronegative element is:

A) O

B) Cl

C) F

D) N

✅ Answer

C) F

---

16. Non-metallic character is generally maximum toward the:

A) Bottom-left of the periodic table

B) Top-right of the periodic table

C) Centre only

D) Bottom-right only

✅ Answer

B) Top-right

---

17. Metallic character and electronegativity generally show:

A) Direct relationship

B) Opposite trends

C) No relationship

D) Identical values

✅ Answer

B) Opposite trends

---

18. Which element is expected to have greater electronegativity?

A) Na

B) Cl

C) K

D) Rb

✅ Answer

B) Cl

---

19. Greater electronegativity generally indicates:

A) Greater non-metallic nature

B) Greater metallic nature

C) Lower electron attraction

D) Larger atomic radius necessarily

✅ Answer

A) Greater non-metallic nature

---

20. Which statement is correct?

A) Electronegativity increases as non-metallic character decreases

B) High electronegativity is generally associated with high non-metallic character

C) Metals are always more electronegative than non-metals

D) Electronegativity has no periodic trend

✅ Answer

B

Q. State the relationship between electronegativity and non-metallic character.

Solution: Electronegativity and non-metallic character are generally directly related. As electronegativity increases, the tendency to attract electrons increases, so non-metallic character also increases.

Electronegativity ↑ → Non-metallic Character ↑

Q. Explain the relationship between electronegativity and non-metallic character.

Solution:

• Non-metals have a strong tendency to attract electrons.
• Electronegativity measures the attraction for a shared pair of electrons.
• Therefore, higher electronegativity generally corresponds to greater non-metallic character.

Q. Explain the periodic variation of electronegativity and non-metallic character.

Solution: Across a period, effective nuclear charge increases and atomic size decreases. Therefore, electronegativity increases and non-metallic character also increases. Down a group, atomic size and shielding effect increase, causing electronegativity and non-metallic character to decrease.

Across a period: EN ↑ → Non-metallic character ↑

Down a group: EN ↓ → Non-metallic character ↓

Q. Discuss the relationship between electronegativity and non-metallic character with examples.

Solution:

Electronegativity is the tendency of an atom in a molecule to attract the shared electron pair towards itself. Non-metallic character represents the tendency of an element to accept or attract electrons.

Thus, both properties are closely related. An element with high electronegativity generally has strong non-metallic character.

For example, fluorine has the highest electronegativity and is highly non-metallic. Across a period, both electronegativity and non-metallic character generally increase.

Electronegativity ↑ → Non-metallic Character ↑

Q. Explain in detail the relationship between electronegativity and non-metallic character and discuss their periodic trends.

1. Electronegativity

Electronegativity is the tendency of an atom in a chemical bond to attract the shared pair of electrons towards itself.

2. Non-metallic Character

Non-metallic character refers to the tendency of an element to attract or gain electrons and to show properties characteristic of non-metals.

3. Relationship

Both properties depend strongly on the ability of an atom to attract electrons. Hence, they generally vary in the same direction.

Electronegativity ↑
↓
Electron-attracting tendency ↑
↓
Non-metallic Character ↑

4. Across a Period

From left to right, effective nuclear charge increases and atomic size decreases. Therefore, electronegativity and non-metallic character generally increase.

5. Down a Group

Down a group, atomic size and shielding effect increase. The attraction for electrons decreases. Hence electronegativity and non-metallic character generally decrease.

Across Period: EN ↑ → Non-metallic Character ↑

Down Group: EN ↓ → Non-metallic Character ↓

Key Point:
Higher electronegativity is generally associated with stronger non-metallic character.

🎯 Quick Revision

Relation: Direct relationship
Across period: Electronegativity ↑, Non-metallic character ↑
Down group: Electronegativity ↓, Non-metallic character ↓
Most electronegative: Fluorine (F)
General location of strong non-metallic character: Upper-right region

How does Electronegativity change across a period from Li to F?

📚 Chapter: Classification of Elements and Periodicity in Properties

📘 Answer

Across the second period, from Li → F, electronegativity generally increases from left to right.

Li < Be < B < C < N < O < F

Fluorine (F) has the highest electronegativity among these elements.

🔍 Why does electronegativity increase?

• Effective nuclear charge increases from Li to F.
• The number of shells remains the same throughout the second period.
• Atomic radius generally decreases.
• Therefore, the nucleus attracts the shared electron pair more strongly.
• Hence, electronegativity increases from Li to F.

Effective Nuclear Charge ↑
↓
Atomic Size ↓
↓
Attraction for Shared Electrons ↑
↓
Electronegativity ↑

📊 Approximate Pauling Electronegativity

Element	Electronegativity
Li	0.98
Be	1.57
B	2.04
C	2.55
N	3.04
O	3.44
F	3.98

✅ Final Answer

Electronegativity increases from Li to F.

Li < Be < B < C < N < O < F

This is mainly due to increasing effective nuclear charge and decreasing atomic radius across the period.

20 MCQs with Answers

1. Electronegativity from Li to F generally:

A) Decreases

B) Increases

C) Remains constant

D) First decreases then increases

✅ Answer

B) Increases

---

2. Which element has the highest electronegativity among Li, Be, B, C, N, O and F?

A) Li

B) C

C) O

D) F

✅ Answer

D) F

---

3. Which element has the lowest electronegativity?

A) Li

B) B

C) N

D) F

✅ Answer

A) Li

---

4. The increase in electronegativity across a period is mainly due to:

A) Decrease in nuclear charge

B) Increase in effective nuclear charge

C) Increase in shells

D) Increase in atomic size

✅ Answer

B) Increase in effective nuclear charge

---

5. From Li to F, the number of electron shells:

A) Increases

B) Decreases

C) Remains the same

D) Becomes zero

✅ Answer

C) Remains the same

---

6. Atomic radius across the second period generally:

A) Increases

B) Decreases

C) Remains constant

D) Doubles

✅ Answer

B) Decreases

---

7. Which has greater electronegativity?

A) Li

B) F

C) Both equal

D) Cannot be determined

✅ Answer

B) F

---

8. Across a period, effective nuclear charge generally:

A) Increases

B) Decreases

C) Remains constant

D) Becomes zero

✅ Answer

A) Increases

---

9. Which element is most electronegative?

A) C

B) N

C) O

D) F

✅ Answer

D) F

---

10. Electronegativity represents the tendency to attract:

A) Neutrons

B) Protons

C) Shared electron pair

D) Nucleus

✅ Answer

C) Shared electron pair

---

11. The correct increasing order is:

A) F < O < N < C

B) C < N < O < F

C) N < C < F < O

D) O < F < C < N

✅ Answer

B) C < N < O < F

---

12. Which has the smallest atomic size among Li to F?

A) Li

B) C

C) O

D) F

✅ Answer

D) F

---

13. Electronegativity generally increases from:

A) Right to left

B) Left to right

C) Bottom to top only

D) Randomly

✅ Answer

B) Left to right

---

14. Which factor opposes the attraction of the nucleus for valence electrons?

A) Shielding effect

B) Nuclear charge

C) Effective nuclear charge

D) Proton number

✅ Answer

A) Shielding effect

---

15. Which has higher electronegativity?

A) B

B) C

C) Both equal

D) Cannot be compared

✅ Answer

B) C

---

16. Fluorine has high electronegativity mainly because of its:

A) Large atomic radius

B) Small atomic radius and high effective nuclear charge

C) Large number of shells

D) Metallic character

✅ Answer

B

---

17. Which sequence represents decreasing electronegativity?

A) Li > Be > B > C > N > O > F

B) F > O > N > C > B > Be > Li

C) Li > F > O > N

D) F > Li > O > C

✅ Answer

B

---

18. Across a period, nuclear charge:

A) Increases

B) Decreases

C) Remains constant

D) Becomes negative

✅ Answer

A) Increases

---

19. Electronegativity of Li is lower than F because Li has:

A) Larger atomic size

B) Smaller atomic size

C) Greater effective nuclear charge

D) More protons than F

✅ Answer

A) Larger atomic size

---

20. The overall trend across Li → F is:

A) Electronegativity ↓

B) Electronegativity ↑

C) No trend

D) Electronegativity becomes zero

✅ Answer

B) Electronegativity ↑

Q. How does electronegativity change from Li to F?

Solution: Electronegativity generally increases from Li to F because effective nuclear charge increases and atomic radius decreases.

Li < Be < B < C < N < O < F

Q. Give reasons for the increase in electronegativity from Li to F.

Solution:

• All elements lie in the same period, so the number of shells remains the same.
• Nuclear charge increases from Li to F.
• Effective nuclear charge increases and atomic radius decreases.
• Therefore, attraction for shared electrons increases.

Q. Explain the variation of electronegativity across the second period from Li to F.

Solution: Across the second period, the number of electron shells remains constant while the number of protons increases. Shielding does not increase substantially because electrons are added to the same principal shell. Thus effective nuclear charge increases, atomic size decreases, and the nucleus attracts shared electrons more strongly.

Li < Be < B < C < N < O < F

Q. Explain why electronegativity increases from Li to F.

Solution:

Electronegativity is the tendency of an atom in a chemical bond to attract the shared pair of electrons towards itself.

From Li to F, the nuclear charge increases progressively. Since all these elements belong to the second period, the added electrons enter the same principal shell. Therefore, effective nuclear charge increases and atomic radius decreases.

The smaller atomic radius brings the shared electron pair closer to the nucleus, while the higher effective nuclear charge increases attraction. Hence electronegativity increases.

Li < Be < B < C < N < O < F

Q. Explain in detail the periodic trend of electronegativity from Li to F.

1. Same Period

Li, Be, B, C, N, O and F all belong to the second period. Therefore, their valence electrons are present in the same principal shell.

2. Increase in Nuclear Charge

As we move from Li to F, the number of protons increases. Thus the positive charge of the nucleus increases.

3. Effective Nuclear Charge

The additional electrons enter the same shell, so the increase in shielding is relatively small. Consequently, effective nuclear charge experienced by the valence electrons increases.

4. Decrease in Atomic Radius

Increasing effective nuclear charge pulls the electron cloud closer to the nucleus. Hence atomic radius decreases from Li to F.

5. Increase in Electronegativity

The smaller atomic size and greater effective nuclear charge make the atom more effective at attracting the shared pair of electrons in a chemical bond.

Nuclear Charge ↑
↓
Effective Nuclear Charge ↑
↓
Atomic Radius ↓
↓
Attraction for Shared Electrons ↑
↓
Electronegativity ↑

Final Order:

Li < Be < B < C < N < O < F

🎯 Quick Revision

Across period: Electronegativity ↑
Atomic size: ↓
Effective nuclear charge: ↑
Number of shells: Same
Highest in Li → F: F
Order: Li < Be < B < C < N < O < F