Question

The most electronegative element in the periodic table is :

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

Hint:

Electronegativity generally increases as you go {up} a group and {to the right} across a period in the periodic table. {Fluorine (F)} is located at the top right (excluding noble gases) and is the most electronegative element. The top three most electronegative elements are: 1. Fluorine (F) 2. Oxygen (O) 3. Nitrogen (N) / Chlorine (Cl) (these two are very close) Mnemonic: {F O N Cl} (pronounced "Foncal") for the order of highly electronegative elements.

Answer 1

The Correct Option is D

Concept: Electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons (or electron density) towards itself when forming a chemical bond. Step 1: Periodic Trends in Electronegativity
Across a Period (Left to Right): Electronegativity generally increases. This is due to increasing nuclear charge (more protons) attracting the bonding electrons more strongly, while the electrons are in the same principal energy level.
Down a Group (Top to Bottom): Electronegativity generally decreases. This is because the bonding electrons are further from the nucleus (in higher energy levels) and are shielded by more inner electron shells, reducing the effective nuclear charge experienced by the valence electrons. These trends mean that the most electronegative elements are located in the upper right-hand corner of the periodic table (excluding noble gases, which typically do not form bonds or have electronegativity defined on the same common scales). Step 2: Identifying the Most Electronegative Element Based on these trends, Fluorine (F) is the most electronegative element. It is in Period 2, Group 17 (Halogens). It has the highest value on various electronegativity scales (e.g., approx. 3.98 on the Pauling scale, often rounded to 4.0). Step 3: Comparing Electronegativity of the Options Approximate Pauling electronegativity values:
Chlorine (Cl): \(\approx 3.16\)
Oxygen (O): \(\approx 3.44\) (Second most electronegative)
Nitrogen (N): \(\approx 3.04\)
Fluorine (F): \(\approx 3.98\) (Most electronegative) The order of electronegativity for these common elements is F>O>Cl \(\approx\) N. Therefore, Fluorine is the most electronegative element in the periodic table.