Question

barium fluoride is an ionic compound. it produces light when x - rays or gamma rays enter it, making it a useful material for radiation detectors. a sample of barium fluoride, cut into a disc shape. which lewis structure correctly represents barium fluoride? choose 1 answer: a ba^{2 + }:f:^{-}ba^{2 + } b ·ba·^{2 - }:f·^{+}·ba·^{2 - } c :f·^{+}·ba·^{2 - }:f·^{+}

Explanation:

Step1: Determine ion - formation of elements

Barium (Ba) is in Group 2 of the periodic table and loses 2 electrons to form a $Ba^{2 + }$ ion. Fluorine (F) is in Group 17 and gains 1 electron to form a $F^-$ ion.

Step2: Analyze the Lewis - structure requirements for barium fluoride

In barium fluoride ($BaF_2$), one $Ba^{2+}$ ion is surrounded by two $F^-$ ions. The Lewis structure should show a $Ba^{2+}$ ion and two $[F:]^-$ ions.

Answer:

None of the given options are correct. The correct Lewis structure of barium fluoride should be $[Ba]^{2 + }2[ :F:]^-$ (but this is not among the provided choices). If we assume there is a mis - typing in the options and we consider the correct ion - charge and bonding concept, the closest correct representation would be that there is one $Ba^{2+}$ and two $F^-$ ions. Since the options are incorrect as presented, if we had to choose the 'least wrong' option based on ion - charge and element identity, we note that barium forms a $2+$ ion and fluorine forms a $1 -$ ion. But again, none of the given options A, B, C correctly represent $BaF_2$. If we assume it's a matter of correct ion - charge representation and ignoring the incorrect number of barium atoms in option A and incorrect charges in B and C, we would say that in a proper Lewis structure of $BaF_2$, we have a $Ba^{2+}$ cation and two $F^-$ anions. But strictly speaking, based on the options given, there is no correct answer.

If we had to force - choose from the given options, we note that barium has a $2+$ charge and fluorine has a $1 -$ charge. Option A has the correct ion - charges for barium and fluorine but has two barium ions instead of one. Option B and C have incorrect ion - charges for barium and fluorine. So, if we had to choose, option A is the 'least wrong' in terms of ion - charge representation for the elements involved, but it is still incorrect in terms of the number of barium ions.

If we assume the question setter made an error in the options and we focus on ion - charge, we can say that the correct Lewis structure of $BaF_2$ has one $Ba^{2+}$ and two $F^-$ ions and the options provided are all incorrect. But if we must choose from the given ones, option A has the correct charge on barium ($2+$) and fluorine ($1 -$) compared to the incorrect charges in B and C, although it has an extra barium ion.

So, if forced to choose: A. $[Ba]^{2+}[:F:]^-[Ba]^{2+}$ (but note this is still incorrect in terms of the number of barium ions in a $BaF_2$ formula unit).