(a) Each county in this state whose voters have adopted a charter form of government and the principal city within its boundaries may create and establish a unified government to perform all of the governmental and corporate functions now, or hereafter authorized to be, performed by the county government and by the government of the principal city in the manner and with the consequences provided for in this chapter. The government of a smaller city within the county may initially or subsequently merge into the unified government by complying with § 7-21-107 or § 7-21-204(c). Any municipality lying in two (2) or more counties may unify with the county in which the majority of its territory lies.

(b) After unification of a charter county government with a municipality, no functions of the governing bodies of the county and the unified municipality, or of the officers of the governing bodies, shall be retained and continued, unless otherwise so provided either in the charter of the unified government or the Constitution of Tennessee.

(c) After the unification, no officer or agency of the county or the unified municipality shall retain any right, power, duty or obligation, unless so provided either in the charter of the unified government or the Constitution of Tennessee; provided, that nothing contained in this chapter shall impair the rights and obligations of notaries public commissioned according to law by the county prior to unification, and such notaries public shall continue to serve for the remainder of their terms as originally commissioned.