Question

Which of the following elements has the most electronegativity: Li, Na, K, or Rb?

• A. Li
• B. Na
• C. K
• D. Rb

Hint:

Electronegativity decreases as you go down a group in the periodic table because the atomic radius increases, reducing the nucleus's ability to attract electrons.

Answer 1

The Correct Option is A

Electronegativity refers to the ability of an atom to attract electrons towards itself when forming a chemical bond. It generally decreases as you move down a group in the periodic table and increases as you move across a period from left to right.
Step 1: Electronegativity Trend in the Periodic Table - Lithium (Li) is in Group 1 of the periodic table, but it is in the second period. Elements in the second period have higher electronegativity compared to elements in the subsequent periods. - Sodium (Na) is in Group 1, but it is in the third period, so its electronegativity is lower than that of lithium. - Potassium (K) is in Group 1, in the fourth period, and has an even lower electronegativity than sodium. - Rubidium (Rb) is in Group 1 and is in the fifth period, so it has the lowest electronegativity of all the elements listed.
Step 2: Conclusion As we move down the alkali metal group, electronegativity decreases. Therefore, Li (Lithium) has the highest electronegativity among the given elements. Thus, the correct answer is \( \boxed{\text{Li}} \).