[mandy9008]

the predominant isotope of ¹⁹⁷₇₉Au has an exact mass of 196.967amu.
what is the total nuclear binding energy of gold in electronvolts per atom?

my work:
mass defect=1.674amu

E=mc²
E=(1.674amu)(3.00*10⁸)²
1.674amu  *   9.31*10⁸eV
       1                   1 amu

E=1.40*10²⁶eV

this is not the right answer!

[ARGOS++]

Dear mandy9008;

1.674amu  *   9.31*10⁸eV    = 1.40*10²⁶eV    this is not the right answer!
       1                   1 amu
 

Check your math!  -  You did a mistake in your final calculation!

1.0 amu = 931.49 MeVolt according to:  http://en.wikipedia.org/wiki/TeV#As_a_unit_of_mass

Good Luck!
                    ARGOS⁺⁺

[mandy9008]

that number for the eV was given to me in the problem hints.

[ARGOS++]

Dear mandy9008;

The number of eV is not the problem, because 9.31 * 10⁸ eV is pretty close to 931.49 MeV.

But remember as I told you:
      Check your math!  -  You did a simple calculation mistake!
      (How can you get such an exponent?)

Good Luck!
                    ARGOS⁺⁺