Write the correct ionic formula for the compound formed between each of the following pairs of ions:b. Ca²⁺ and S²⁻

Verified step by step guidance

1. Identify the charges on each ion: Calcium (Ca) has a charge of +2, and Sulfur (S) has a charge of -2.
2. To form a neutral compound, the total positive charge must balance the total negative charge.
3. Since both ions have charges of equal magnitude but opposite signs (+2 and -2), they will combine in a 1:1 ratio.
4. Write the formula by placing the symbols for calcium and sulfur together, without any subscripts, as the charges are already balanced.
5. The resulting ionic formula is simply the combination of the two elements in their simplest ratio.

Key Concepts

Ionic Compounds

Ionic compounds are formed when positively charged ions (cations) and negatively charged ions (anions) bond together through electrostatic forces. The overall charge of the compound must be neutral, meaning the total positive charge must balance the total negative charge. Understanding how to combine these ions based on their charges is essential for writing correct ionic formulas.

Charge Balance

Charge balance is a fundamental principle in forming ionic compounds. Each ion has a specific charge, and when combining ions, the total positive charge from cations must equal the total negative charge from anions. For example, in the case of Ca²⁺ (with a +2 charge) and S²⁻ (with a -2 charge), one of each ion combines to create a neutral compound, CaS.

Chemical Formula Representation

The chemical formula of an ionic compound represents the ratio of ions in the compound. It is written with the cation first followed by the anion, and subscripts indicate the number of each ion needed to achieve charge balance. For the compound formed from Ca²⁺ and S²⁻, the formula is CaS, indicating one calcium ion and one sulfide ion combine to form the compound.