Atomic and Nuclear Physics Answers

the electric field near the origin is given by E=(3xi+5j)v/m. imagine a gaussian surface shaped like a cube with one corner at the origin and another at (-2,2,2) meters, with all faces parallel to x-y,x-z, or y-z planes. what is the net flux through gaussan cube?

Living matter has an activity of 260 Bq/kg due to carbon – 14. If a sample of wood from a

burial site has an activity of 155 Bq/kg, estimate the age of the site. (Assume the half – life

of carbon – 14 is 5730 years).

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.

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?