which is larger ,an atomic mass unit based on the current standard or one based on the mass of a Be-9 atom set at exactly 9 amu? PLEASE REPLY SOON .

Be would be lighter on this scale than it is on the C-12 scale
however
nature would not be changed by this new definition
the ratio of masses between any two given atoms of elements would be the same
so
the measured masses of all atoms would be slightly less by this new definition
an atom twice as heavy as Be would now weigh 18 as opposed to 18.02 by C-12 standard

Of course, the mass of the atoms have not changed in an absolute sense
we have just redefined the standard of measurement