Atomic and Nuclear Physics Answers

Show that the group velocity is zero at edge of the first Briclouin zone for a linear monoatomic chain.

The energy of the lowest allowed level for an electron in a 1-D box is 10.0 eV. Can the electron ever have an energy of 200 eV? Justify.

For a motion of a particle of mass μ in a spherically symmetric potential show that
L²and Lzcommute with the Hamiltonian

Calculate the mean kinetic and potential energies of a simple harmonic oscillator
which is in its ground state.

For the operator A = a x + i b p where a and b are constants, calculate [A, x] and
[A, A].

1kg mass placed on the moon will weigh

Cobalt 60 is used in many applications where gamma radiation is required. The half-life of cobalt 60 is 5.26 years.
a. Find the decay constant
b. If a sample has an initial activity of 2*10^(15) Bq, what will its activity be after 3 years?

The electrical conductivity of monovalent Na metal is 117m1017.2−−Ω×. Calculate the relaxation time and the drift velocity in a field of 100 V m−1. Take density of Na to be 0.97 gm cm−3.

. A tank of C2Cl4 (containing 37Cl) is used as a neutrino detector to
measure the flux of neutrinos produced in the sun. A neutrino has a
cross-section for interacting with matter of approximately 10 fb.
a. Write down the nuclear decay that occurs when a 37Cl nucleus
interacts with a solar neutrino (Hint: try rearranging beta decay
equations).
b. Assuming there is a material with approximately 1024 protons
per cm3
: what is the probability that the neutrino will interact
when travelling through 10 m of detector?

With which of the following is the weak nuclear force associated?





a.
lightning
c.
ocean tides
b.
nuclear decay
d.
static cling