Question

what is the name of the ionic compound cose?
cobalt (ii) selenide
copper (i) sulfide
cobalt (i) selenide
copper (ii) selenide

Explanation:

• Identify the elements:
• The symbol \(Co\) represents cobalt.
• The symbol \(Se\) represents selenium.
• Determine the charge of cobalt:
• Selenium (\(Se\)) typically has a charge of \(- 2\) in ionic compounds.
• For the compound \(CoSe\) to be neutral, cobalt (\(Co\)) must have a charge of \(+2\) (since \(+2+(-2) = 0\)).
• Name the compound:
• For ionic compounds with transition metals (like cobalt), we use Roman numerals in parentheses to indicate the charge of the metal ion.
• The anion (\(Se^{2 -}\)) is named selenide.

Answer:

cobalt (II) selenide