Answer: The chemical formula for the compound will be

Step-by-step explanation:
Calcium is the 20th element of the periodic table having electronic configuration of
![[Ar]4s^2](https://img.qammunity.org/2018/formulas/chemistry/high-school/scdzae3rdn8hrul4o3iyupeyr05olgmuo8.png)
This element will loose 2 electrons and thus shows an oxidation state of +2 units.
Iodine is the 53rd element of the periodic table having electronic configuration of
![[Kr]5s^24d^(10)5p^5](https://img.qammunity.org/2018/formulas/chemistry/middle-school/460pmdsano6ryr20fo0zkdwst7b5fjp81r.png)
This element requires 1 electron and thus shows an oxidation state of -1 units.
So, by criss-cross method, the oxidation state of the ions will get exchanged and they form the subscripts of the other ions. This results in the formation of a neutral compound.
Hence, the chemical formula for the compound formed will be
