# Physics to Elena

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Estimate the total binding energy for copper.
550 MeV

Estimate the energy, in joules, needed to break a 3.0g copper penny into its constituent nucleons.
E= in Joules

Physics - Elena, Wednesday, May 8, 2013 at 6:33am
Number of atoms is
N= N(A)•m/μ =
=6.022•10²³•0.003/63.5•10⁻³=2.85•10²².
Number of nucleons (protons+neutrons) =
=2.85•10²²•63=1.8•10²⁴.
Energy = 1.8•10²⁴•550•10⁶•1.6•10⁻¹⁹ =1.58•10⁸ J

Thanks for the help but 1.58x10^8 J is wrong n I recalculated you calculation I got 1.58x10^14 J but that was also wrong so could you plz help me out.

• Physics to Elena -

I believe that the correct answer is 1.58•10¹⁴ J.

• Physics to Elena -

Thatz what I got too but itz still wrong :/ I don't know why please help me...thanks

• Physics to Elena -

Number of nuclei
N=n•N(A) = (m/μ) • N(A)=
=(3 g)•(6.022•10²³ nuclei/mol)/(63 g/mol)=2.87•10²² nuclei
The energy required to break all the copper nuclei into their constituent protons and
neutrons is
(550 MeV ) •(2.87•10²² nuclei) =1.56•10²⁵ MeV =
=1.56•10³¹eV =2.5•10¹² J