Question

why are metals malleable?
the electrons are shared between two metal ions and this holds the atoms together
the electrons are delocalized and able to move between the atoms
the electrons are held tightly within the lattice structure making it strong
they are shiny

Explanation:

Metals are malleable because of their metallic bonding. In metallic bonding, electrons are delocalized (they are not attached to a single atom) and can move freely between atoms. When a force is applied to a metal (to shape it - malleability), the layers of metal atoms can slide over each other. The delocalized electrons act as a 'sea' that allows this sliding without the structure breaking. The first option describes covalent - like electron sharing (not metallic), the third option describes a structure that would not be malleable (tight electron holding would prevent layer - sliding), and the fourth option (shininess) is a different property (related to electron interaction with light) not related to malleability.

Answer:

The electrons are delocalized and able to move between the atoms.