Potassium and iodine have formed a bond. prior to this the potassium gave up an electron. it became a positive ion neutral atom negative ion shared ion

Option (a) is the correct answer.

Explanation:

A bond formed by sharing of electrons is known as a covalent bond. And, a bond formed due to transfer of electron from one atom to another is known as ionic bond.

For example, potassium has 1 valence electron and iodine have 7 valence electrons.

So, in order to attain stability potassium will transfer its one valence electron to iodine when they chemically combine together.

It results in the formation of KI that is, potassium iodide.

When an atom loses an electron then it acquires a positive charge and it is called a cation. Whereas if an atom gains an electron then it acquires a negative charge and it is called an anion.

Therefore, when potassium gave up an electron it became a positive ion.

it forms an anion that has a larger radius. anions have a negative charge and are larger than the original atom.