The metallic bond consists of a series of
metals atoms that have all donated their
valence electrons to an electron cloud that
permeates the structure. This electron cloud is
frequently referred to as an electron sea. It
might help to visualize the electron sea model
as if it were a box of marbles that are
surrounded by water. The marbles represent
the metal atoms and the water represents the
electron sea.
Kernels
Since the metal atoms have all lost their valence
electrons, they are now positive ions. However,
because they are not associated with ionic bonding,
these  positive ions have a special name. The  
positive ions within a metallic solid are known as
Kernels.
Metallic Bonds  - Streaming