Question

question 1.3
which answer below correctly lists the formulas for the ions that form the ionic compound given?
calcium fluoride → ca²+ f-
aluminum bromide → al³+ br²-
lithium oxide → li²+ o-
potassium nitride → k³+ n-

Explanation:

Step1: Analyze calcium fluoride

Calcium (\(Ca\)) is in group 2 of the periodic table, so it loses 2 electrons to form \(Ca^{2 +}\). Fluorine (\(F\)) is in group 17, it gains 1 electron to form \(F^{-}\). The formula for calcium fluoride is \(CaF_{2}\), and the ions are \(Ca^{2+}\) and \(F^{-}\).

Step2: Analyze aluminium bromide

Aluminium (\(Al\)) is in group 13, it loses 3 electrons to form \(Al^{3+}\). Bromine (\(Br\)) is in group 17, it gains 1 electron to form \(Br^{-}\), not \(Br^{2 -}\).

Step3: Analyze lithium oxide

Lithium (\(Li\)) is in group 1, it loses 1 electron to form \(Li^{+}\), not \(Li^{2+}\). Oxygen (\(O\)) is in group 16, it gains 2 electrons to form \(O^{2 -}\), not \(O^{-}\).

Step4: Analyze potassium nitride

Potassium (\(K\)) is in group 1, it loses 1 electron to form \(K^{+}\), not \(K^{3+}\). Nitrogen (\(N\)) is in group 15, it gains 3 electrons to form \(N^{3 -}\), not \(N^{-}\).

Answer:

calcium fluoride → \(Ca^{2+}\), \(F^{-}\)