Question

atoms of mg combine with atoms of f to form a compound. atoms of which of the following elements combine with atoms of f in the same ratio?

Explanation:

Step1: Determine the charge of Mg and F

Mg is in Group 2, so it has a charge of \(+2\). F is in Group 17, so it has a charge of \(-1\). The formula for the compound formed by Mg and F is \(MgF_2\) (using the criss - cross method: \(Mg^{2+}\) and \(F^{-}\), so \(MgF_2\)).

Step2: Analyze each element

• Li: Li is in Group 1 (\(Li^{+}\)), F is \(-1\). The formula is \(LiF\) (ratio \(1:1\), not \(1:2\)).
• Ba: Ba is in Group 2 (\(Ba^{2+}\)), F is \(-1\). Using the criss - cross method, the formula is \(BaF_2\) (ratio \(1:2\)).
• Al: Al is in Group 13 (\(Al^{3+}\)), F is \(-1\). The formula is \(AlF_3\) (ratio \(1:3\)).
• Cl: Cl and F are both non - metals. They form covalent compounds. Chlorine and fluorine can form various compounds like \(ClF\), \(ClF_3\), \(ClF_5\) etc., not in a \(1:2\) ratio similar to \(MgF_2\) (ionic compound ratio).

Answer:

B. Ba