Arrange the following elements in order of increasing electronegativity: Na, Cl, S, Mg.

• A. Cl < S < Mg < Na
• B. Mg < Na < Cl < S
• C. Na < Mg < S < Cl
• D. S < Cl < Na < Mg

Answer: (C)

Verified step by step guidance

1. Recall that electronegativity is a measure of an atom's ability to attract electrons in a chemical bond. It generally increases across a period (left to right) in the periodic table and decreases down a group (top to bottom).
2. Identify the positions of the elements Na, Mg, S, and Cl on the periodic table: Na (Group 1, Period 3), Mg (Group 2, Period 3), S (Group 16, Period 3), and Cl (Group 17, Period 3).
3. Since all elements are in the same period (Period 3), compare their electronegativities by moving from left to right: electronegativity increases from Na to Mg to S to Cl.
4. Write the order of increasing electronegativity based on their positions: Na < Mg < S < Cl.
5. Verify that this order matches the known trend and the correct answer given, confirming that Na has the lowest electronegativity and Cl the highest among the four elements.