Question

lead is malleable, so it can be pounded into flat sheets without breaking. how does the bonding within lead help to explain this property?
metallic bonds involve valence electrons that are removed from one atom and given to another, so the pounding helps the electrons move.
covalent bonds involve valence electrons that are shared between two metal atoms, so the bonds are strong enoug to resist the pounding.
metallic bonds involve many valence electrons shared by many atoms, so the bonds can move around as the metal is pounded.
covalent bonds involve valence electrons that are removed from one atom and given to another, so the pounding helps the electrons move.

Explanation:

Lead is a metal. Metallic bonding has a "sea of electrons" where many valence electrons are shared by many atoms. When a metal like lead is pounded (deformed), the metallic bonds (due to the delocalized electrons) can adjust. Covalent bonds (involving sharing between specific atoms, not the case in metals) and the description of electron transfer (like in ionic bonds, not metallic) in other options are incorrect.

Answer:

Metallic bonds involve many valence electrons shared by many atoms, so the bonds can move around as the metal is pounded.