Answer: Option (a) is the correct answer.
Step-by-step explanation:
A chemical bonding in a substance occurs when there is exchange of electrons between the atoms. These electrons are present in the outermost orbital are actually away from the nucleus of the atom.
Due to which there is no force of attraction between nucleus or valence electrons. Hence, it is easy for the outermost orbital to lose electron.
Whereas nucleus of an atom contains neutrons and protons. And, changes in the nucleus of an atom leads to nuclear reactions.
Therefore, we can conclude that the configuration of the outermost orbital determines chemical bonding characteristics.