Write a chemical formula. . . Ca2+ and S2-
The Correct answer and Explanation is :
The chemical formula formed by calcium ions (Ca²⁺) and sulfide ions (S²⁻) is CaS. This formula represents calcium sulfide, a compound formed by the combination of calcium and sulfur.
Explanation:
- Ionic Bonding: Calcium (Ca) is a metal in Group 2 of the periodic table, meaning it has two electrons in its outermost shell. To achieve a stable electron configuration, calcium tends to lose these two electrons, resulting in a positively charged ion, Ca²⁺. On the other hand, sulfur (S) is a non-metal in Group 16, with six electrons in its outer shell. Sulfur needs two additional electrons to complete its octet and achieve stability. Therefore, it gains two electrons, forming a negatively charged ion, S²⁻.
- Charge Balance: The charges of the ions are critical for determining the formula of the resulting compound. In this case, the Ca²⁺ ion has a charge of +2, while the S²⁻ ion has a charge of -2. The charges balance each other out: +2 from calcium and -2 from sulfur. This neutral charge indicates that one calcium ion will pair with one sulfide ion to form a neutral compound.
- Chemical Formula Representation: The formula CaS is indicative of a 1:1 ratio of calcium ions to sulfide ions in the compound. It shows that for every calcium ion, there is one sulfide ion, resulting in a stable ionic compound.
- Properties of Calcium Sulfide: Calcium sulfide is a white or yellowish solid that can react with water to produce hydrogen sulfide gas, a compound known for its characteristic rotten egg smell. It is also used in various applications, including phosphorescent materials, fertilizers, and in the production of sulfur-containing compounds.
In summary, the correct chemical formula for the combination of Ca²⁺ and S²⁻ ions is CaS, representing calcium sulfide, an ionic compound formed by the transfer of electrons from calcium to sulfur.