In your own words, explain why there are two chloride ions for every calcium ion in calcium chloride (CaCl2).

Sure, let's break it down step by step.

1. Understanding the Elements: Calcium (Ca) is a metal, and chlorine (Cl) is a non-metal. When they form a compound, they create an ionic bond.

2. Valence Electrons and Charges: Calcium has two valence electrons and tends to lose these two electrons to achieve a stable electron configuration, becoming a Ca²⁺ ion. Chlorine, on the other hand, has seven valence electrons and needs one more electron to achieve stability, becoming a Cl⁻ ion when it gains an electron.

3. Charge Balance: In an ionic compound, the total positive charge must balance the total negative charge. Since calcium loses two electrons, it becomes Ca²⁺. Each chlorine atom gains one electron, becoming Cl⁻.

4. Ratio of Ions: To balance the charges, one Ca²⁺ ion (which has a +2 charge) needs two Cl⁻ ions (each with a -1 charge) to neutralize the overall charge. Therefore, for every calcium ion, there are two chloride ions.

5. Chemical Formula: This balance of charges is reflected in the chemical formula CaCl₂, indicating one calcium ion and two chloride ions.

So, there are two chloride ions for every calcium ion in calcium chloride because calcium loses two electrons (becoming Ca²⁺) and each chlorine gains one electron (becoming Cl⁻), requiring two chloride ions to balance the charge of one calcium ion.