Metals conduct electricity through the movement of electrons in solid as well as molten state. The conductivity is dependent on the number of valence electrons. Electrical conductivity of a substance depends on the ability of the solid to flow electrons from the valence band to a conduction band. In a crystal lattice, the atomic orbitals of the atoms overlap and form molecular orbitals with very close values in energy, and form a band. A partially filled valence or an overlapping valence band are featured in metals. The band gap, even if negligible can be determined in metals using UV-Vis spectrometry. Options (i), (ii) and (iv) are correct.