Question

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

Answer 1

Calcium iodide (chemical formula CaI2)

Answer 2

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

Step-by-step 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`