Which of the following elements is most reactive due to its tendency to lose one electron and form a +1 ion?

• A. Al (aluminum)
• B. Na (sodium)
• C. Mg (magnesium)
• D. Ne (neon)

Answer: (B)

Verified step by step guidance

1. Identify the group of each element in the periodic table to understand their typical ion formation tendencies. Sodium (Na) is in Group 1 (alkali metals), aluminum (Al) is in Group 13, magnesium (Mg) is in Group 2 (alkaline earth metals), and neon (Ne) is in Group 18 (noble gases).
2. Recall that elements in Group 1 have a single electron in their outermost shell, which they tend to lose easily to achieve a stable noble gas electron configuration, forming a +1 ion.
3. Understand that aluminum (Al) typically loses three electrons to form a +3 ion, magnesium (Mg) loses two electrons to form a +2 ion, and neon (Ne) is chemically inert and does not tend to form ions due to its full valence shell.
4. Compare the reactivity based on the ease of losing electrons: sodium (Na) loses one electron most readily, making it highly reactive and favoring the formation of a +1 ion.
5. Conclude that sodium (Na) is the most reactive element among the options due to its strong tendency to lose one electron and form a +1 ion.