To determine the correct description of the compound formed by potassium (K) and sulfur (S), we need to balance the charges of the ions involved and then identify the correct formula and name for the compound.
1. Identify the charges:
- Potassium (K) has a charge of +1.
- Sulfur (S) has a charge of -2.
2. Balance the charges to make a neutral compound:
- Since potassium has a charge of +1, we need two potassium ions to balance the -2 charge of one sulfur ion.
- Thus, two potassium ions (each with a +1 charge) will balance one sulfur ion (with a -2 charge).
3. Determine the chemical formula:
- To achieve charge balance, we use two potassium ions and one sulfur ion.
- Therefore, the chemical formula for the compound is \( K_2S \).
4. Name the compound:
- The cation (positive ion) is named first, followed by the anion (negative ion).
- Potassium (K) forms the cation, and its name remains 'potassium.'
- Sulfur (S) forms the anion, and its name changes to 'sulfide.'
- Therefore, the name of the compound is 'potassium sulfide.'
Given these points, the best description of the compound is:
- The chemical formula is \( K_2S \), and the name is 'potassium sulfide.'
So, the correct answer is:
The chemical formula is [tex]\( K_2S \)[/tex], and the name is potassium sulfide.
