Question

why do metals conduct
they are shiny
the electrons are shared between two metal ions
the electrons are held tightly within the lattice
the electrons are delocalised and able to move

Explanation:

Metals conduct electricity because of the delocalized electrons in their structure. These electrons are not bound to a single atom and can move freely throughout the metal lattice. This movement of electrons allows for the conduction of electric current. The statement "The electrons are delocalised and able to move" correctly explains the conduction mechanism in metals. The other options are incorrect: "They are shiny" refers to a physical property (luster) not related to conduction; "The electrons are shared between two metal ions" is not the correct description of electron behavior in metals (metallic bonding involves a sea of delocalized electrons, not sharing between two ions in the way described); "The electrons are held tightly within the lattice" would prevent conduction as electrons need to be able to move for conduction to occur.

Answer:

The electrons are delocalised and able to move.