Final answer:
The chemical formula for calcium selenide is CaSe, as the charges of calcium (Ca²+) and selenium (Se²−) ions balance out in a 1:1 ratio. Calcium carbonate is a compound with a ratio of Ca:C:O of 1:1:3. Calcium bromide and aluminum oxide have the formulas CaBr₂ and Al₂O₃, respectively.
Step-by-step explanation:
In response to the question about predicting the chemical formula for calcium selenide, given that calcium oxide is CaO, we can infer the formula using the charges of calcium and selenium ions. Calcium, represented as Ca, forms a Ca²+ ion and selenium forms a Se²− ion. Since both ions have charges that are numerically equal but opposite, they combine in a 1:1 ratio, similar to how calcium and oxygen combine in calcium oxide. Therefore, the chemical formula for calcium selenide would be CaSe.
Addressing the information provided about calcium carbonate, we can state the following:
- Calcium carbonate is a compound, as it is made up of more than one element chemically combined in a fixed ratio.
- The ratio of Ca : C : O atoms in the formula CaCO₃ is 1:1:3.
For calcium bromide and aluminum oxide, the correct chemical formulas are CaBr₂ and Al₂O₃, respectively, based on the charges and balancing the total charge for the ionic compounds.