Which of the following elements exhibits the greatest metallic character?

• A. Al
• B. Na
• C. Mg
• D. K

Answer: (D)

Verified step by step guidance

1. Understand that metallic character refers to how readily an element can lose electrons to form positive ions, which generally increases as you move down a group in the periodic table and decreases as you move from left to right across a period.
2. Identify the positions of the given elements (Al, Na, Mg) and the correct answer (K) on the periodic table: Na, Mg, and Al are in period 3, while K is in period 4, group 1.
3. Recall that elements in group 1 (alkali metals) have the highest metallic character in their respective periods because they have a single electron in their outermost shell that is easily lost.
4. Compare the elements: Na (group 1, period 3), Mg (group 2, period 3), Al (group 13, period 3), and K (group 1, period 4). Since K is below Na in group 1, it has a larger atomic radius and lower ionization energy, increasing its metallic character.
5. Conclude that potassium (K) exhibits the greatest metallic character among the listed elements because it is further down the group and more willing to lose its valence electron.