Question

What is the formula of a compound formed between iodine (I) and calcium (Ca)?

Answer 1

Answer: The chemical formula for the compound will be $CaI_2$

Explanation:

Calcium is the 20th element of the periodic table having electronic configuration of $[Ar]4s^2$

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 $[Kr]5s^24d^{10}5p^5$

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 $CaI_2$

Answer 2

Calcium iodide (chemical formula CaI2)