Question

In a sea of aluminum atoms...each aluminum atom gives up three valence electrons to the sea of free moving conduction electrons...and the metal is a conductor of electrical current...but why do the aluminum atoms do this in the first place?

Answer 1

it actually does'nt give them up....
the size of proton is far far far less than that of the atoms ..so the electrons occupy the surrounding area ..
and since the aluminium has low ionization potential it can easily lose electrons to get the nearest noble gas configuration...

Answer 2

if any can happen than it will happen
if the thermal energy of the system is enough to overcome the energy barriers of the atom
than it will loose the electrons