Answer:
Valence electrons form bonds to create molecules and compounds because they are weaker than the electrons found closer to the nucleus.
Step-by-step explanation:
Electrons, being negatively charged particles definitely get attracted to the positively charged nucleus. Thus the distance between electrons and nucleus determines the strength of bonding of electrons to the atom.
Valence electrons are present in the outermost shell of the atom and thus the distance between the nucleus and valence electrons is large when compared with the electrons in the inner shells.
In order to form bonds to make molecules and compounds electrons should be weakly bonded to the parent atom. Thus the weak bond with parent atom makes valence electrons the active participants in a chemical reaction.