Question 15 of \( 43> \) Determine the formula unit for the compound formed when each pairs of ions interact.

When positively charged ions (cations) and negatively charged ions (anions) come together, they form ionic compounds. The formula unit represents the simplest ratio of these ions in the compound. For example, when sodium ions (Na⁺) and chloride ions (Cl⁻) come together, they form sodium chloride (NaCl), where one sodium ion pairs with one chloride ion in a 1:1 ratio. In some cases, like magnesium ions (Mg²⁺) and oxide ions (O²⁻), two oxide ions interact with one magnesium ion to form magnesium oxide (MgO). Here, the formula unit reflects the balanced charges of the cations and anions involved. Understanding the charge balance is crucial for writing the correct formula for various ionic compounds!