—   but by  the vibration   of  individual
molecules   or  a   portion of  the lattice,    which   is
transferred to  neighboring areas.  This    transfer
of  vibration   is  a   much    slower  and less
efficient   process than    electron    movement,   and
nonmetals   are therefore   usually referred    to  as
thermal or  electrical  insulators, rather  than
conductors. Liquids and gases,  because their
molecules   are relatively  far apart,  are very
poor    conductors.
The conductivity    of  a   material    determines
its behavior    on  the stove.  The better  the
conductor,  the faster  a   pan heats   up  and cools
off,    and the more    evenly  heat    is  distributed
across  the pan bottom. Uneven  heating creates
hot spots   that    can burn    foods:  during  frying,
for example,    or  the boiling down    of  a   puree   or
sauce.
Conduction  Within  a   Food    Heat    also    travels
from    the outside to  the center  of  a   solid   piece
of  food    —   a   piece   of  meat    or  fish    or  vegetable