# Homework Help: Nuclear physics

1. Nov 13, 2007

### david1362

hi guys, iam kinda stuck on 2 problems. here is what it is :

The nuclear fission reaction of uranium-235 with one neutron produces germanium-81, 5 neutrons and another element, what element is that? whats the atomic number andatmoic mass,?give the equation.

2. howmuch energy is released in the complete fission of one kg of U-235 oxide? given that energy fission of one atom of uranium is 3.2 x 10^-11 J

Thanks guys

2. Nov 13, 2007

### malawi_glenn

show work done. what have you tried?

3. Nov 13, 2007

### david1362

i mentioned i was stuck

the thing u just said in ur reply wont help at all, how would u like me to give u such an answer to ya? you would have been better not replying

4. Nov 13, 2007

### malawi_glenn

The rules of these forums is that you show work done and that you have attempted a solution. If you have not read the rules, then i suggest you do it.

Use the template, and if Som eone replied to me in that manner i did to you, i would admit that i have done a misstake and would try to come up with an attempt to a solution.

I can give you a hint, count the number of neutrons and protons before and after the reaction and see what yo u get. (for the first problem)

Last edited: Nov 13, 2007
5. Nov 13, 2007

### Astronuc

Staff Emeritus
We respectfully request that students show work and effort in solving the HW problems when asking for assistance, as malawi_glenn appropriately indicated.

http://www.webelements.com/

We know the start U (Z=92, A=235) + 1 n -> Ge(Z=?, A=81) + ??? + 5n.

Determine the change in Z and the balance the neutrons. In a nucleus of an isotope, the number of neutrons N = A - Z, where A is the atomic mass and Z is the atomic number.

One has to go to a chart of nuclides for the actual mass of a particular radionuclide.

http://www.nndc.bnl.gov/chart/ - click on a location in the chart, the use zoom 1, upper right, in order to see details.

6. Nov 13, 2007

### david1362

Thanks alot, i appreciate it, sorry i lose temper, but iam under so much pressure in this class. thanx again, I hope i can help you with your questions soon.