Empirical formula for these ionic materials

[omni]

I have to write an empirical formula for these ionic materials:
Al N
Sr I

so i know that Al gives 3 electrons and N will get 3 electrons.
to make them to be neutral so the empirical formula of Al and N need to look like this AlN?

and for Sr and I i know Sr gives electrons and I get 1 so how the empirical formula of them need to be if i want to make them neutral Sr1I2 ?

thanks

 

[Borek]

Looks OK, although no idea why you call these empirical formulas. I would call them theoretical ones - you have predicted them using some basic quantum chemistry, not calculated based on experimental results.

 

[omni]

well this how they call them in the book.
and i mean Sr gives 2 electrons