Question

For the hypothetical compound AX2, which of the following statements is true?
a.) A is a nonmetal from Group 3A, and X is a metal from Group 1A.

b.) A is a metal from Group 1A, and X is a metal from Group 7A.

c.) A is a metal from Group 3A, and X is a nonmetal from Group 5A.

d.) A is a metal from Group 2A, and X is a nonmetal from Group 7A.

Answer 1

They're assuming the compound is ionic.

what type of ions do the groups listed form?

which one makes sense in terms balancing the charge so the compound is neutral?

Answer 2

Cations? Possibly c. I can't figure this one out. I'm fine one nearly all the other questions on my test but this one is really complicated and I'm missing the concept.

Answer 3

one is going to be a cation and the other an anion.

for example: b) A is a metal from Group 1A, and X is a metal from Group 7A

Group 1A metals make +1 cations
Group 7A nonmetals make -1 anions

so if the compound is \(AB_2\) then the charges won't cancel out (+1 + 2(-1)=-1).

Answer 4

so you can eliminate b as an option

Answer 5

Well, Group 2A metals make +2 cations, right? And Group 7A metals make -1. So (+2 + 2(-1) = 0) Does that make the answer D because we get 0 from the equation?

Answer 6

yep thats correct

Answer 7

Oh cool:) Thank you!