Strontium and Ammonia: Forming Sr[NH3]6

[Puchinita5]

Homework Statement

I had a problem in inorganic chemistry that required I know what forms when strontium dissolves in ammonia. Looking at the answer, it says that

Sr + NH3 ---> Sr[NH3]6


I'm not sure how I would have been able to predict that this is what formed.

Homework Equations

The Attempt at a Solution

 

[AGNuke]

You can't. Its an ammide complex. You need to know it.