What is the name of the compound with the chemical formula MgSe? Spelling counts.
The Correct Answer and Explanation is:
The correct name of the compound with the chemical formula MgSe is:
Magnesium selenide
Explanation
Magnesium selenide (MgSe) is an ionic compound composed of magnesium (Mg) and selenium (Se). To understand its name, it’s important to examine both the elements involved and the rules for naming binary ionic compounds.
1. Magnesium (Mg):
Magnesium is a metal from Group 2 of the periodic table, meaning it is an alkaline earth metal. These elements typically form ions with a +2 charge (Mg²⁺). In compound formation, magnesium readily loses two electrons to achieve a stable noble gas configuration.
2. Selenium (Se):
Selenium is a nonmetal from Group 16 (also known as the chalcogens). It typically forms an ion with a -2 charge (Se²⁻) by gaining two electrons. This is because selenium wants to fill its outer electron shell to become stable.
3. Ionic Compound Formation:
To form a neutral ionic compound, the total positive and negative charges must balance. Magnesium contributes a +2 charge, and selenium contributes a -2 charge. Since the charges are equal and opposite, only one of each ion is needed to balance the compound, giving the formula MgSe.
4. Naming Rules:
For binary ionic compounds like MgSe:
- The name of the metal (cation) comes first and stays the same: magnesium.
- The name of the nonmetal (anion) comes second, and its ending changes to -ide: selenide (from selenium).
Thus, MgSe is named magnesium selenide.
Spelling is important because:
- “Selenide” (not “selenite” or “selenate”) specifically indicates a -2 anion.
- The suffix “-ide” is used only for binary compounds (two elements only).
Therefore, the correct and complete name is magnesium selenide
.