Atomic and Nuclear Physics Answers

Neutrons from a nuclear reactor are brought into thermal equilibrium by repeated collisions in heavy water at T = 300k. What is the average energy (in eV) and the typical wavelength of the neutrons ? Explain why they are diffracted when they pass through a crystalline solid.

The half life of Rn is 3.82 days. Determine the time it takes for 60% of the Rn to decay, the activity of 10 mg of Rn.

Neutrons from a nuclear reactor are brought into thermal equilibrium by
repeated collisions in heavy water at T ˆ 300 K. What is the average
energy (in eV) and the typical wavelength of the neutrons? Explain why
they are diffracted when they pass through a crystalline solid.

An electric field E can pull an electron out of a Helium atom in the same time that the electron takes
to go around the nucleus once. Then E is

The 14 C activity of some ancient Peruvian corn
was found to be 10 disintegrations per minute
per gram of C. If present-day plant life shows 15
dmp /g, how old is the Peruvian corn? The half
life of 14 C is 5730 years.

The energy release in the reaction A(d, p)B is Q. Show that the neutron separation
energy for nucleus B is Sn = Q + ε, where ε is the binding energy of the deuteron (d)

Àn oil drop carrying a charge of -3.2*epx-20 C is held stationary between two horizontal parallel plates 5.00mm apart when a p.d. of 500V is applied between the plates. Calculate the mass of the oil drop.

X - ray spectrum of a cobalt largest ( Z = 27 ) contains strong K(Alpha) line of wavelength
0.1785 nm and a weak line having wavelength of 0.1537 nm due to impurities. The atomic number of impurity element is?

Consider three identical, ideal capacitors. The first capacitor is charged to a voltage V and thendisconnected from the battery. The other two capacitors, initially uncharged and connected in series,are then connected across the first. What is the final voltage across the first capacitor?