Beryllium (Be) and fluorine (F) combine to make the compound BeF2. What is the chemical name for this compound?
The Correct Answer and Explanation is:
The chemical name for the compound BeF₂ is beryllium fluoride.
Explanation:
The naming of ionic compounds follows the conventions set by the International Union of Pure and Applied Chemistry (IUPAC), which considers the elements involved and their oxidation states.
- Cation (positive ion) identification:
- Beryllium (Be) is a Group 2 element in the periodic table. As a Group 2 metal, beryllium typically forms a cation with a 2+ charge (Be²⁺). This is because elements in Group 2 lose two electrons to achieve a stable electron configuration, similar to that of the nearest noble gas.
- The name of the cation is simply the name of the element, in this case, “beryllium.”
- Anion (negative ion) identification:
- Fluorine (F) is a halogen, located in Group 17 of the periodic table. Fluorine typically gains one electron to form a negatively charged anion, F⁻. This results in a fluoride ion, which is named by adding the suffix “-ide” to the root of the element’s name, turning “fluor” into “fluoride.”
- Naming the compound:
- Ionic compounds are named by first stating the cation (positively charged ion) followed by the anion (negatively charged ion). The cation is named first because it appears before the anion in the formula.
- Since BeF₂ consists of one beryllium ion (Be²⁺) and two fluoride ions (F⁻), the compound is named beryllium fluoride. There is no need to use Roman numerals to indicate the charge of beryllium in this case because beryllium always forms a 2+ cation.
Thus, BeF₂ is beryllium fluoride, and its structure is a simple ionic lattice where each beryllium ion is surrounded by two fluoride ions.