Which of the following elements will likely form a negative ion (anion) in its ionic compounds?

• A. Na
• B. Cl
• C. Mg
• D. Al

Answer: (B)

Verified step by step guidance

1. Step 1: Understand that elements form ions by either losing or gaining electrons to achieve a stable electron configuration, often resembling the nearest noble gas.
2. Step 2: Recall that metals tend to lose electrons to form positive ions (cations), while nonmetals tend to gain electrons to form negative ions (anions).
3. Step 3: Identify the elements given: Na (sodium), Mg (magnesium), Al (aluminum), and Cl (chlorine). Note that Na, Mg, and Al are metals, while Cl is a nonmetal.
4. Step 4: Recognize that sodium (Na), magnesium (Mg), and aluminum (Al) typically lose electrons to form cations: Na⁺, Mg²⁺, and Al³⁺ respectively.
5. Step 5: Understand that chlorine (Cl) tends to gain one electron to form the chloride ion (Cl⁻), which is a negative ion (anion). Therefore, Cl is the element that will likely form an anion.