Which elements commonly form ionic compounds with chlorine? (Give two examples.)

Which elements commonly form ionic compounds with chlorine? (Give two examples.)

• A. Sodium and Magnesium
• B. Calcium and Iron
• C. Chlorine and Fluorine
• D. Sodium and Potassium

Answer: (D)

When chlorine forms ionic compounds, it takes on a negative charge as chloride (Cl−) while the metal partner loses electrons to become a positive ion. Metals that readily give up electrons to create stable +1 cations pair most cleanly with chloride. Sodium and potassium are classic examples: each loses one electron to become Na+ or K+, and they bond ionically with Cl− to form NaCl and KCl. These salts are the textbook illustration of how metal cations balance the chloride anion in ionic compounds. Other options don’t illustrate this simple, common pairing as clearly. Chlorine and fluorine are both nonmetals and tend to share electrons rather than form ionic bonds with each other. Calcium and iron can form chlorides, but iron has variable oxidation states and its chlorides can have more covalent character, so they’re not as straightforward a case of a simple +1 metal with chloride. Magnesium can form ionic chlorides too, but sodium and potassium best demonstrate the typical +1 metal–chloride ionic pairing the question aims to highlight.

When chlorine forms ionic compounds, it takes on a negative charge as chloride (Cl−) while the metal partner loses electrons to become a positive ion. Metals that readily give up electrons to create stable +1 cations pair most cleanly with chloride. Sodium and potassium are classic examples: each loses one electron to become Na+ or K+, and they bond ionically with Cl− to form NaCl and KCl. These salts are the textbook illustration of how metal cations balance the chloride anion in ionic compounds.

Other options don’t illustrate this simple, common pairing as clearly. Chlorine and fluorine are both nonmetals and tend to share electrons rather than form ionic bonds with each other. Calcium and iron can form chlorides, but iron has variable oxidation states and its chlorides can have more covalent character, so they’re not as straightforward a case of a simple +1 metal with chloride. Magnesium can form ionic chlorides too, but sodium and potassium best demonstrate the typical +1 metal–chloride ionic pairing the question aims to highlight.