Final answer:
In the electron-sea model, metals consist of positive ions in a 'sea' of delocalized electrons, allowing them to conduct electricity effectively. This model describes the ease through which metals allow electrical charge to flow and explains their characteristic luster and ductility.
Step-by-step explanation:
The electron-sea model of metallic bonding describes how metals bond through a structure where positively charged metallic ions are surrounded by a 'sea' of delocalized electrons. This 'sea' allows the electrons to move freely through the metal, which is why metals are excellent electrical conductors. This model fits with choice b) Metals have a "sea" of delocalized electrons that can move freely.
The presence of delocalized Valent electrons in this 'sea' allows for the transfer of electrical charge with ease, contributing to the high conductivity of metals. Additionally, these movable electrons can absorb and re-emit light energy, which explains the lustrous appearance of metals. Because the electrons are not bound to any particular atom, the structure remains intact while allowing the atoms within the metal to move around, leading to properties such as ductility and malleability.