Predict the chemical formula for the ionic compound formed by (a) Ca2+ and Br-

Verified step by step guidance

1. Identify the charges of the ions involved: Calcium ion (Ca^{2+}) has a charge of +2, and Bromide ion (Br^{-}) has a charge of -1.
2. To form a neutral ionic compound, the total positive charge must balance the total negative charge.
3. Determine the ratio of ions needed to balance the charges. Since Ca^{2+} has a +2 charge and Br^{-} has a -1 charge, you will need two Br^{-} ions to balance one Ca^{2+} ion.
4. Write the chemical formula by placing the cation first followed by the anion, using subscripts to indicate the number of each ion needed. In this case, one Ca^{2+} ion pairs with two Br^{-} ions.
5. The chemical formula for the ionic compound is CaBr_{2}, indicating one calcium ion and two bromide ions.

Key Concepts

Ionic Compounds

Ionic compounds are formed when atoms transfer electrons, resulting in the formation of charged ions. These compounds typically consist of a metal cation and a non-metal anion. The electrostatic attraction between the oppositely charged ions leads to the formation of a stable ionic lattice structure.

Charge Balance

In ionic compounds, the total positive charge must balance the total negative charge to achieve electrical neutrality. This means that the ratio of cations to anions is determined by their respective charges. For example, if a cation has a charge of +2 and an anion has a charge of -1, two anions are needed to balance one cation.

Chemical Formula Representation

The chemical formula of an ionic compound is represented by the symbols of the constituent ions, with subscripts indicating the number of each ion needed to achieve charge balance. For example, in the case of calcium bromide, the formula is CaBr2, indicating one calcium ion and two bromide ions.