Given the name, select the correct formula for each ionic compound:
Sodium chloride
Sodium chloride is an ionic compound composed of sodium ions and chloride ions. Sodium (Na) is an alkali metal located in Group 1 of the periodic table, and it loses one electron to achieve a stable octet, forming a cation with a charge of \(+1\), denoted as \(Na^+\). Chlorine (Cl) is a halogen located in Group 17, which gains one electron to achieve stability, forming an anion with a charge of \(-1\), denoted as \(Cl^-\).
Ionic compounds must be electrically neutral, meaning the total positive charge must be equal to the total negative charge. We need to determine the ratio of sodium ions to chloride ions that results in a net charge of zero. Since the sodium ion has a charge of \(+1\) and the chloride ion has a charge of \(-1\), a one-to-one ratio will balance the charges perfectly: \(1 \times (+1) + 1 \times (-1) = 1 - 1 = 0\).
With the one-to-one ratio established, we write the symbol for the cation followed by the anion. The ratio of 1:1 leads to the empirical formula \(NaCl\). Comparing this result with the given options, we find that \(NaCl\) is the correct chemical formula.
Understanding how ionic compounds form is fundamental to chemistry and everyday life. For instance, common table salt (sodium chloride) is used in cooking to enhance flavor and as a preservative. By knowing the charges of individual ions, you can predict the properties of many substances around you, from the salt in your food to the minerals found in rocks and ocean water.