Which of the following pairs of elements exhibits the most striking difference in their chemical properties due to their classification on the periodic table?

• A. Na and Cl
• B. Fe and Co
• C. C and Si
• D. O and S

Answer: (A)

Verified step by step guidance

1. Step 1: Understand that elements in the periodic table are grouped into categories such as metals, nonmetals, and metalloids, and their chemical properties are largely influenced by their group and period positions.
2. Step 2: Analyze each pair to determine their classifications and positions on the periodic table: Na (sodium) is an alkali metal, Cl (chlorine) is a halogen (nonmetal); Fe (iron) and Co (cobalt) are both transition metals; C (carbon) and Si (silicon) are both metalloids or nonmetals in the same group; O (oxygen) and S (sulfur) are both nonmetals in the same group.
3. Step 3: Recognize that pairs within the same group or similar classification tend to have similar chemical properties, while pairs from different groups or classifications show more striking differences.
4. Step 4: Conclude that the pair Na and Cl, being from different groups (alkali metal vs halogen) and different classifications (metal vs nonmetal), exhibits the most significant difference in chemical properties.
5. Step 5: Summarize that the difference in chemical behavior between Na and Cl is due to their positions in the periodic table and their distinct elemental classifications, which affect their reactivity and bonding tendencies.