Question

what is the correct formula for aluminum bromide?
question 5
what are the roman numerals used for?
charge of cation
charge of anion
subscript for cation
subscript for anion

Explanation:

Step1: Determine the charge of cation and anion

Aluminum (\(Al\)) has a charge of \(+3\) (\(Al^{3+}\)), bromide (\(Br\)) has a charge of \(-1\) (\(Br^{-}\)).

Step2: Use criss - cross method

To balance the charges, we need 3 \(Br^{-}\) ions for 1 \(Al^{3+}\) ion.

for Question 5:
Roman numerals are used to indicate the charge of cations (especially for transition metals which can have multiple oxidation states). For example, in \(FeCl_{2}\) (iron(II) chloride) and \(FeCl_{3}\) (iron(III) chloride), the Roman numerals (II and III) show the charge of the iron cation. Anions usually have fixed charges and don't use Roman numerals in this context. Subscripts are related to the ratio of ions in the formula, not indicated by Roman numerals.

Answer:

\(AlBr_{3}\)