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. (b) Potassium and sulfur

Verified step by step guidance

1. Identify the charges of the ions formed by each element. Potassium (K) typically forms a +1 cation (K+), and sulfur (S) typically forms a -2 anion (S^2-).
2. Determine the simplest ratio of ions that will result in a neutral compound. Since potassium has a +1 charge and sulfur has a -2 charge, two potassium ions are needed for every sulfur ion to balance the charges.
3. Write the chemical formula by placing the cation first followed by the anion. Since two potassium ions are needed for each sulfur ion, the formula is K2S.
4. Name the compound by first naming the cation (potassium) and then the anion with an 'ide' suffix. Since the anion is sulfur, its name changes to sulfide.
5. Combine the names of the cation and anion to get the full name of the compound: potassium sulfide.

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 properties of ionic compounds include high melting and boiling points, and they typically dissolve in water to form electrolytes.

Valence Electrons

Valence electrons are the outermost electrons of an atom and are crucial in determining how an element will react chemically. In the case of potassium (K), it has one valence electron, while sulfur (S) has six. The transfer of potassium's valence electron to sulfur allows both elements to achieve stable electron configurations, leading to the formation of an ionic bond.

Chemical Nomenclature

Chemical nomenclature is the system of naming chemical compounds based on their composition and structure. For binary ionic compounds, the name typically consists of the cation's name followed by the anion's name with its ending changed to '-ide.' In this case, potassium forms the cation K⁺ and sulfur forms the anion S²⁻, resulting in the compound potassium sulfide (K₂S).