Q.According to Pauling scale, the element with the highest electronegativity is _________.
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Electronegativity Variability
The Intuition: Why "Pull" Isn't Fixed
Imagine two children playing tug-of-war with a rope. One child is stronger, so the rope moves toward her. Now imagine that same child playing tug-of-war with a different opponent — the rope might move less, or even the other way. The "pull" of a child depends on who she's pulling against.
Electronegativity works the same way. It measures how strongly an atom pulls shared electrons toward itself in a chemical bond. But here's the key: an atom's pull changes depending on what it's bonded to. A carbon atom bonded to hydrogen pulls electrons gently; the same carbon bonded to oxygen pulls much harder. The atom's "strength" isn't a fixed number — it varies with its chemical surroundings.
This is why electronegativity is a relative property, not an absolute one like mass or charge. You can't measure an atom's electronegativity in isolation — you can only compare it with another atom in a bond.
The Precise Statement
Electronegativity variability means that the electronegativity of an element is not a single, universal constant. It depends on:
- The oxidation state of the atom (higher oxidation state → higher electronegativity)
- The hybridisation of the atom's orbitals (more s-character → higher electronegativity)
- The chemical environment — what other atoms or groups are attached nearby
For example, consider carbon:
| Carbon in | Electronegativity (Pauling scale) | Reason |
|---|---|---|
| CH4 (methane) | ~2.5 | sp3 hybridised, low s-character |
| C2H4 (ethene) | ~2.75 | sp2 hybridised, more s-character |
| C2H2 (ethyne) | ~3.0 | sp hybridised, highest s-character |
The same carbon atom pulls electrons more strongly when it uses sp orbitals (50% s-character) than when it uses sp3 orbitals (25% s-character). This is because s-orbitals are closer to the nucleus, so electrons in them feel a stronger effective nuclear charge.
A common mistake is to treat electronegativity as a fixed number you can look up in a table. Those tables give average values for common bonding situations — they're useful approximations, not fundamental constants. The actual electronegativity in a specific molecule can differ significantly.
Why This Matters
Electronegativity variability explains many chemical phenomena that fixed values cannot:
- Why CO2 is nonpolar despite having polar C=O bonds — the two bonds pull equally in opposite directions.
- Why CCl4 is nonpolar but CHCl3 is polar — the different atoms around carbon change its effective electronegativity.
- Why the same element can act as both an oxidising and reducing agent — in different oxidation states, its electron-pulling power changes. …
On the Pauling electronegativity scale, fluorine is assigned the highest value (4.0) of all elements. …
Fluorine has the highest Pauling electronegativity (4.0).
Electronegativity increases across a period and decreases down a group, so it is greatest at the top-right of the periodic table (excluding noble gases). Fluorine, being small with a high nuclear charge, attracts b …
- CBSE 2026Set ANNUAL1 markMCQQ.Which of the following is the most electronegative element in periodic table ?(a) N(b) O(c) Cl(d) F
›Reveal solutionSolution
Fluorine is the most electronegative element.
Electronegativity increases across a period and decreases down a group, so it is greatest at the top-right (excluding noble gases). Fluorine, being small and highly effective at attracting bonding electro …
- CBSE 2026Set ANN1 markQ.According to Pauling scale, the element with the highest electronegativity is _________.
›Reveal solutionSolution
Fluorine has the highest Pauling electronegativity (4.0).
Electronegativity increases across a period and decreases down a group, so it is greatest at the top-right of the periodic table (excluding noble gases). Fluorine, being small with a high nuclear charge, attracts b …
- CBSE 2026Set ANNUAL1 markQ.What is diagonal relationship ?
›Reveal solutionSolution
Diagonal relationship is the close similarity in properties between certain second-period elements and the element diagonally placed to them in the third period.
On moving from left to right in a period atomic size decreases and electronegativity/ionic character changes, while moving down a group has the opposite effect. These two opposing trends partly cancel along a diagonal, so an element of period 2 and the element diagonally below-right of it in period 3 end up with a similar charge-to-size ratio (similar polarising power) and hence similar properties. …
- CBSE 2025Set ANNUAL1 markMCQQ.Which of the following is most electronegative?(a) Carbon(b) Silicon(c) Lead(d) Tin
›Reveal solutionSolution
Carbon is the most electronegative of the Group 14 elements listed.
Carbon, silicon, tin and lead all belong to Group 14. Electronegativity decreases down a group because atomic size increases and the valence electrons are farther from, and more shielded from, the nucleus. Carbon, being at the top of the gro …
- CBSE 2025Set sz1 markMCQQ.Select the correct one: The most electronegative element in the periodic table is:(a) Nitrogen(b) Oxygen(c) Chlorine(d) Fluorine
›Reveal solutionSolution
Fluorine is the most electronegative element in the periodic table.
Electronegativity generally increases across a period (left to right) and decreases down a group, because atoms get smaller and hold their valence electrons — and any shared electrons — more tightly as effective nuclear charge increases and atomic radius decreases. Fluorine sits at the top-right of the main periodic table (excluding noble gases, which normally don't form bonds), giving it the smallest atomic radius among electronegativity-forming elements and the strongest pull on bonding electrons, with …
- CBSE 2023Set ANNUAL1 markMCQQ.The most electronegative element is :(a) Chlorine(b) Iodine(c) Oxygen(d) Fluorine
›Reveal solutionSolution
Fluorine is the most electronegative element.
Electronegativity is the tendency of an atom to attract shared electrons. It increases across a period (rising nuclear charge, smaller size) and decreases down a group. The maximum is reached at the top-right of the periodic table (excluding noble gases), at fluorine, which has a Pauling electronegativity of about 4.0 - higher …
- CBSE 2021Set ANNUAL1 markMCQQ.Which of the following has the highest electronegativity?(a) Li(b) Be(c) B(d) C
›Reveal solutionSolution
Electronegativity rises across Period 2 as nuclear charge increases and atomic radius shrinks, so carbon (the rightmost element of the four listed) is the most electronegative.
Electronegativity is the tendency of an atom in a molecule to attract the shared pair of bonding electrons towards itself. Within a period, as we move left to right, the nuclear charge increases while the number of shells stays the same, so the outer electrons are held more tightly and electronegativity increases.
…
- CBSE 2020Set ANNUAL1 markMCQQ.The electronegativity of F atom is:(a) 3.5(b) 4.5(c) 3.0(d) 4.0
›Reveal solutionSolution
On the Pauling scale, fluorine is assigned electronegativity 4.0, the maximum value used as the reference point for the whole scale.
Electronegativity measures an atom's tendency to attract the shared pair of electrons in a covalent bond toward itself. On the Pauling scale (the most commonly used scale, based on bond energy differences), values range roughly from about 0.7 (for caesium, the least electronegative common element) up to 4.0 for fluorine, the most electronegative element of all.
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