Question

What would the chemical formula of the compound look like if you combine calcium and iodine?

Answer 1

Hint: Approach this question by using the valence electrons or valency of each element given in the question to form the compound. Here we are provided with calcium and iodine which reacts together to form an ionic compound known as calcium iodide. So here we need to write the chemical formula of this compound.

Complete answer:
Calcium (denoted by Ca) is the element that belongs to the group of alkaline-earth metals. It is the abundant metallic element in the human body and also the fifth most abundant element in Earth’s crust. As it belongs to the second group, this means it has 2 electrons in its valence shell and has a +2 valency after the donation of 2 electrons.
-Iodine is an element with the chemical symbol I, atomic number 53 and belongs to the halogen group of the periodic table. It is the heaviest of all the stable halogens and exists as a lustrous, purple-black non-metallic solid at standard conditions. Since it belongs to the halogen family, it has 7 valence electrons in its outermost shell and only requires 1 to complete its octet.
-When calcium reacts with iodine, it forms an inorganic salt or ionic compound called calcium iodide. The reaction takes place as follows:-
$Ca(s)+{{I}_{2}}(s)\to Ca{{I}_{2}}(s)$
As here we can see that Ca donates its 2 electrons to each atom of iodine in order to complete their octets. They turn into ions and attract each other which results in the formation of ionic compounds.
-Hence, the chemical formula of the compound looks like $Ca{{I}_{2}}$if we combine calcium and iodine with each other.

Note:
-This compound is white in color and easily soluble in acetone and alcohol.
-When calcium iodide reacts with an acid, it liberates hydrogen iodide.
-It is mainly used as analysis agents and especially in photography and pharmaceutical industries.