Each of the following pairs of elements will react to form a binary ionic compound. Write the formula of each compound formed, and give its name. (a) Sodium and iodine

Key Concepts

Ionic Compounds

Ionic compounds are formed when atoms transfer electrons, resulting in the formation of positively charged cations and negatively charged anions. These oppositely charged ions attract each other, creating a stable compound. The formula of an ionic compound reflects the ratio of the ions involved, ensuring that the overall charge is neutral.

Nomenclature of Ionic Compounds

The naming of ionic compounds follows specific rules. The cation (positive ion) is named first, followed by the anion (negative ion). For monatomic ions, the name of the anion is derived from the element's name, typically by adding the suffix '-ide' to the root. For example, sodium (Na) and iodine (I) combine to form sodium iodide.

Electron Configuration and Reactivity

The reactivity of elements is largely determined by their electron configuration, particularly the number of valence electrons. Sodium, with one valence electron, readily loses it to achieve a stable electron configuration, while iodine, with seven valence electrons, gains an electron to complete its octet. This electron transfer is fundamental in the formation of ionic bonds.