The board may (i) sell, at public or private sale, or exchange, lease (as lessor or lessee), mortgage, pledge, subordinate its interest in, or otherwise dispose of the real property, which includes the superjacent airspace, except airspace provided for in § 15.2-2030, which may be subdivided and conveyed separate from the subjacent land surface, of the county; and (ii) purchase any real estate as may be necessary for the erection of all necessary county buildings. However, no such land shall be disposed of unless and until the governing body has held a public hearing concerning such disposal. The board may acquire by purchase, gift, devise, bequest, grant, lease, or otherwise title to, or any interests or rights of less than fee-simple title in, any real property within its jurisdiction, for any public purposes. The initial term of any lease shall not exceed seventy-five years, provided such lease term is not prohibited by the Constitution of Virginia. The terms and provisions of any lease shall be prescribed by the county board, provided that any lease shall have a clause to the effect that at the termination of such lease it shall not be renewed if required for any of the purposes mentioned in § 15.2-1639, and that upon termination, all improvements thereon shall revert to the county and the real property including all improvements erected thereon shall revert to the county and shall be free from any encumbrance at the time of such reversion. Such real property including all improvements situated thereon may be mortgaged or pledged by the lessee for the term of its lease. If a lease allows a lessee to mortgage or pledge the property, it may also provide that the board has the right to take all action necessary to cure the default if the lessee defaults. The board may lease real property to private entities under terms which allow the private entities to build office and commercial buildings on the property and to use the office and commercial space itself or lease it to others. The leases by the board to private entities may provide that the rent to be paid the board is to be based in total or in part on a percentage of the profit the private entity gains from the operation of the development on the leased real property; however, the board may not participate in the management or operation of the private commercial activity on the site except during such reasonable period as it is necessary for the board to operate the property in order to protect its interest in the property if the developer defaults on the lease or on a mortgage or pledge of the property. As soon as reasonably possible the county shall provide for management and operation of the property by a private developer. The board may lease space in the improvements constructed on the land which it leases to the private entities for use by the county government and county constitutional officers, if it pays fair market rent for the use of the space and if the lease of its land is not conditioned on the lease of such space. The lease of such space by the board may be for any terms of years not prohibited by the Virginia Constitution. This section shall not be construed to in any way affect the requirements of §§ 15.2-1638, 15.2-1643 or § 16.1-69.50.