What would the chemical formula of the compound look like if you combined Calcium and Iodine?

1 Answer
Mar 4, 2017

Answer:

The formation reaction is:

#Ca(s) + I_2(s) rarr CaI_2(s)#

Explanation:

#Ca(s) + I_2(s) rarr CaI_2(s)#

This is in fact a redox reaction: calcium metal metal is oxidized up to #Ca^(2+)#, and #I_2# is reduced to iodide anion.

How do you know this occurs save by memory? Another way is to consider their positions in the Periodic Table. Calcium is a Group 2 metal, that has 2 valence electrons; its reactivity is chatacterized by its tendency to LOSE its valence electrons to form the #Ca^(2+)# ion. And iodine, as an oxidizing Group 17 non-metal, tends to GAIN electrons to form the iodide ion, #I^-#. Electrical neutrality demands that the salt of #Ca^(2+)# and #I^-# form an a #1:2# ratio. Why?