What is the empirical formula for aluminium selenide?
What is the common oxidation state of aluminum? Combine that information with the valency for selenium that you came up with in the previous question to come up with the formula for aluminum selenide. If your are being given this question, presumably you now know how to come up with ionic formulas.
To determine the empirical formula for aluminium selenide, we first need to determine the oxidation state of aluminum.
The common oxidation state of aluminum is +3. This means that aluminum typically loses three electrons to achieve a stable configuration.
Next, we need to consider the valency of selenium. Based on the periodic table, selenium has a valency of -2. This means that selenium typically gains two electrons to achieve a stable configuration.
To combine the oxidation state of aluminum (+3) and the valency of selenium (-2) to form a compound with a neutral charge, we need to have two aluminum atoms for every three selenide ions.
As a result, the empirical formula for aluminium selenide is Al2Se3.