* Calcium (Ca): Calcium is in Group 2 of the periodic table, meaning it has 2 valence electrons.
* Iodine (I): Iodine is in Group 17 (or VIIA), meaning it has 7 valence electrons.
The Transfer:
* Calcium wants to lose its 2 valence electrons to achieve a stable octet (8 electrons in its outer shell).
* Each iodine atom wants to gain 1 electron to achieve a stable octet.
Therefore, one calcium atom transfers two valence electrons, one to each of the two iodine atoms.
