Question A.)

An electron, rest mass 511 keV, is trapped in an infinite potential well of width 173 pm (picometers). How much energy is required to excite the electron from state n = 1 to state n = 8.1? Give your answer in eV, give the units and use 3 significant figures.

]Question B.)

How many neutrons does the nuclide ¹⁴₇N contain?

Question C.)

An sample of total activity 9.3Ci (microcurie) consists of a radioactive isotope with half life 5 hours. How many radioactive atoms are there in the sample?

Question D.)

An electron (rest mass 511 keV) is in a 1 dimensional infinite potential well of width 615 pm. If the electron was in state n = 12, but was to de-excite, what is the lowest energy photon that can be emitted? Put your answer in eV and give units.

Question E.)

A sample of a radioactive isotope was found to have an activity of 8.6Ci. After 20 days, the sample had an activity of 4.1Ci. What is the half-life of the sample in days? No units are needed.