Based on periodic trends in metallic character, which of the following elements is likely to be the most reactive?

• A. Mg
• B. Si
• C. Al
• D. Na

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 is closely related to reactivity in metals.
2. Recall the periodic trend that metallic character increases as you move down a group (column) in the periodic table and decreases as you move from left to right across a period (row).
3. Identify the positions of the given elements: Mg (magnesium) is in group 2, period 3; Al (aluminum) is in group 13, period 3; Si (silicon) is in group 14, period 3; and Na (sodium) is in group 1, period 3.
4. Compare their metallic characters based on their group positions: elements in group 1 have the highest metallic character in their period, followed by group 2, then groups 13 and 14, which are more metalloid or nonmetallic.
5. Conclude that Na, being in group 1, has the highest metallic character and thus is the most reactive metal among the options, even though it was not listed initially with Mg, Si, and Al.