Question

An element from Group 13 bonds with an element from Group 17. Which formula correctly depicts the correct chemical formula for elements from these two groups?
Responses
A AlCl3AlCl 3
B B3IB 3 I
C BFBF
D BrGa3BrGa 3
Question 2
PART B
Based on your answer to Part A, what is the oxidation number for the elements that combined?
Responses
A -3 & +1-3 & +1
B +1 & -1+1 & -1
C +1 & -3+1 & -3
D +3 & -1

Answer 1

To solve these questions, we need to identify the common bonding behavior of Group 13 and Group 17 elements.

### Question 1
Group 13 includes elements like aluminum (Al) and gallium (Ga), while Group 17 includes halogens such as chlorine (Cl), bromine (Br), and iodine (I). When a Group 13 element bonds with a Group 17 element, the typical bonding ratio is that the Group 13 element has a +3 oxidation state and the Group 17 usually has a -1 oxidation state. Therefore, to balance charges:

- Aluminum forms AlCl₃ (3 chlorides for 1 aluminum),
- Gallium forms GaI₃ (3 iodides for 1 gallium).

Among the given options, **AlCl₃** is the correct formula.

So the answer to Question 1 is:
**A. AlCl₃**

### Question 2
From the bonding described, the oxidation states are:
- For aluminum (Group 13) = +3
- For chlorine (Group 17) = -1

So the answer to Question 2 based on the oxidation numbers is:
**D. +3 & -1**