# Mass defect of hydrogen-2 from electon binding energy of electron in ground state

1. May 13, 2010

### rayray2216

The problem statement, all variables and given/known data:

the binding energy for the electron in the ground state of hydrogen-2 is 13.6ev
what is the corresponding mass defect of the hydrogen atom in amu (atomic mass units)
not sure if you need atmoic mass of the hysgrogen atom its given to be 2.014102u

Relevant equations:

not really sure but i know that nuclear binding energy=Mass defect x c^2
so BE/c^2=Mass deffect

931.58=uc^2

The attempt at a solution:
Havent really got a clue how to start i thought you would just use the above formula but i feel i am wrong :s

1 amu = 931.46 MeV/c2 = 0.93146 GeV/c2
1 MeV/c2 = 1.074 × 10–3 amu
Thus 13.6 eV = 13.6 x 10^-6 MeV
=>13.6 eV = 13.6 x 10^-6 x 1.074 x 10^-3 x (3 x 10^8)^2 amu
=>13.6 eV = 1.32 x 10^9 amu

but i feel this is very wrong

Last edited: May 13, 2010
2. May 13, 2010

### rayray2216

im desperate can anyone help....point me in the right direction ????