[appleseed]

Hello!

I was asked to write the reaction for the formation of zinc iodide from zinc and iodine, so I put down ZnI,

after looking on the net i found that it is actually ZnI2, but how am i supposed to figure out that the charge of Zn is 2+, because i thought that you coudlnt figure out the charge from the periodic table because it is a transition metal. But something llike iodine you can just find out from the periodic table

Is it purely from memorization???

Could you give me other examples where transition metals only have one oxidation state?


Thank you !!!
all help appreciated

[tamim83]

Zn always, to my knowledge, forms a 2+ ion.  In fact, all of the elements in that group (Group 12) forms 2+ ions.  This is because after losing the 4s electrons Zn still has a a closed n=3 shell, which is a very stable electron configuration.  It's not all memorization this time, it is based off of electronic structure. 

Hope this helps some.