Question

Which element has the highest electronegativity?

• A. Lithium
• B. Sodium
• C. Potassium
• D. Fluorine

Hint:

A good mnemonic for the most electronegative elements is "FONClBrISCH".
It stands for Fluorine, Oxygen, Nitrogen/Chlorine, Bromine, Iodine, Sulfur, Carbon, Hydrogen in decreasing order.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Electronegativity is defined as the tendency of an atom to attract a shared pair of electrons towards itself in a covalent bond.
It is a relative property and depends on the atom's effective nuclear charge and atomic radius.

Step 2: Key Formula or Approach:
The approach requires applying the general periodic trends of electronegativity across periods and down groups in the periodic table.
Electronegativity increases across a period (left to right) and decreases down a group (top to bottom).

Step 3: Detailed Explanation:
Let us evaluate the positions of the given elements in the periodic table.
Options (A) Lithium, (B) Sodium, and (C) Potassium are all alkali metals situated in Group 1.
They are located on the far left side of the periodic table, meaning they have very large atomic radii and low effective nuclear charges.
Consequently, these metals have very low electronegativity values, as they tend to easily lose electrons rather than attract them.
Option (D) Fluorine is a halogen located in Group 17 and Period 2.
It is positioned at the top right of the periodic table, excluding the relatively inert noble gases.
Due to its small atomic size and high effective nuclear charge, it exhibits an extremely strong pull on shared electrons.
Therefore, Fluorine is universally recognized as the most electronegative element, assigned a maximum value of 4.0 on the Pauling scale.

Step 4: Final Answer:
Fluorine has the highest electronegativity among the given elements.