When magnesium reacts with chlorine, which ionic compound is formed?

• A. Mg2Cl
• B. Mg2Cl3
• C. MgCl2
• D. MgCl

Answer: (C)

Verified step by step guidance

1. Identify the charges of the ions formed by magnesium and chlorine. Magnesium typically forms a cation with a charge of +2, written as \(\mathrm{Mg^{2+}}\), and chlorine forms an anion with a charge of -1, written as \(\mathrm{Cl^-}\).
2. Determine the ratio of ions needed to balance the total positive and negative charges in the compound. Since magnesium has a +2 charge and chlorine has a -1 charge, two chloride ions are needed to balance one magnesium ion.
3. Write the formula of the ionic compound by combining one \(\mathrm{Mg^{2+}}\) ion with two \(\mathrm{Cl^-}\) ions, resulting in \(\mathrm{MgCl_2}\).
4. Confirm that the total positive charge equals the total negative charge to ensure the compound is electrically neutral: \(+2\) from magnesium and \$2 \times (-1) = -2$ from chlorine.
5. Conclude that the correct formula for the ionic compound formed when magnesium reacts with chlorine is \(\mathrm{MgCl_2}\).