Final answer:
Both the electron sea model and band theory involve delocalized electrons; however, band theory introduces energy bands and band gaps, providing a more detailed explanation of electrical conductivity.
Step-by-step explanation:
The question asks for one similarity and one difference between the electron sea model and the band theory of metallic bonding. A similarity between the two theories is that both involve delocalized electrons, which are not tied to any specific atom but move freely throughout the metal. This characteristic explains metals' ability to conduct electricity because these electrons can flow and carry charges.
A difference between the electron sea model and band theory is that the electron sea model is a simpler concept that does not fully account for the differences in properties of conductors, semiconductors, and insulators, whereas band theory provides a more comprehensive explanation by considering energy bands and band gaps. In band theory, electrons fill the energy levels in a more complex manner, forming bands that can be filled or partially filled, giving rise to different conducting properties.