Question

Which of the following is the most electronegative element in the periodic table ?

• A. Oxygen
• B. Nitrogen
• C. Flourine
• D. Chlorine

Hint:

Electronegativity increases towards the top-right of the periodic table. {F}luorine (F) is the king of electronegativity – it's the most "electron-greedy" element. Remember the top few: {F>O>N \(\approx\) Cl}. (Often remembered by the mnemonic FONCl - "Foncal").

Answer 1

The Correct Option is C

Concept: Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons towards itself when it is part of a chemical bond. Step 1: Trends in Electronegativity in the Periodic Table % Option (H) Across a Period (Left to Right): Electronegativity generally increases. This is because the number of protons (nuclear charge) increases, pulling the bonding electrons more strongly, while the electrons are added to the same principal energy level. % Option (I) Down a Group (Top to Bottom): Electronegativity generally decreases. This is because the bonding electrons are in higher energy levels, further from the nucleus, and are shielded by more inner electron shells, reducing the nucleus's attraction for them. As a result of these trends, the most electronegative elements are found in the upper right-hand corner of the periodic table (excluding noble gases, which generally don't form bonds readily or have conventionally defined electronegativity values in the same scale). Step 2: Identifying the Most Electronegative Element Fluorine (F) is located at the top of Group 17 (Halogens) and in the second period. Due to its position, it has the highest electronegativity value of all elements. On the Pauling scale (a common scale for electronegativity), fluorine is assigned a value of 3.98 (often rounded to 4.0). Step 3: Comparing the electronegativity of the given options Approximate Pauling electronegativity values: % Option (J) (1) Oxygen (O): \(\approx 3.44\) (Second most electronegative) % Option (K) (2) Nitrogen (N): \(\approx 3.04\) (Third/Fourth most electronegative, close to Chlorine) % Option (L) (3) Fluorine (F): \(\approx 3.98\) (Most electronegative) % Option (M) (4) Chlorine (Cl): \(\approx 3.16\) (Third/Fourth most electronegative, close to Nitrogen) The order of electronegativity for these common highly electronegative elements is: F>O>Cl \(\approx\) N. Therefore, Fluorine is the most electronegative element in the periodic table. (Note: The spelling in the option is "Flourine", the correct spelling is "Fluorine").