Rank the following elements in order of increasing electron affinity:Cs, Hg, F, S

• A. Hg < S < F < Cs
• B. Hg < F < S < Cs
• C. Cs < S < F < Hg
• D. Cs < S < Hg < F
• E. Cs < Hg < S < F

Answer: (E)

Verified step by step guidance

1. Understand the concept of electron affinity: Electron affinity is the amount of energy released when an atom in the gaseous state accepts an electron. Generally, elements with higher electron affinity are more likely to gain electrons.
2. Recall the periodic trend: Electron affinity generally increases across a period from left to right and decreases down a group in the periodic table. This is because atoms become more electronegative as you move across a period, and less electronegative as you move down a group.
3. Identify the position of each element in the periodic table: Cs (Cesium) is in Group 1, Hg (Mercury) is in Group 12, S (Sulfur) is in Group 16, and F (Fluorine) is in Group 17.
4. Apply the periodic trend to rank the elements: Since electron affinity increases across a period and decreases down a group, Cs, being in Group 1, will have the lowest electron affinity. Hg, being in Group 12, will have a higher electron affinity than Cs but lower than S and F. S and F are in Groups 16 and 17 respectively, with F having the highest electron affinity.
5. Conclude the ranking based on the trend: The correct order of increasing electron affinity is Cs < Hg < S < F.