Questions from Modern Physics

Q: The unstable isotope 40K is used for dating rock samples. Its

The unstable isotope 40K is used for dating rock samples. Its half-life is 1.28 * 109 y. a. How many decays occur per second in a sample containing 1.63 * 10-6 g of 40K? b. What is the activity of t...

Q: For a particle in a finite potential well, is it correct

For a particle in a finite potential well, is it correct to say that each bound state of definite energy is also a state of definite wavelength? Is it a state of definite momentum? Explain.

Q: As a health physicist, you are being consulted about a spill

As a health physicist, you are being consulted about a spill in a radiochemistry lab. The isotope spilled was 400 µCi of 131Ba, which has a half-life of 12 days. a. What mass of 131Ba was spilled? b...

Q: Measurements on a certain isotope tell you that the decay rate decreases

Measurements on a certain isotope tell you that the decay rate decreases from 8318 decays/min to 3091 decays/min in 4.00 days. What is the half-life of this isotope?

Q: A radioactive isotope has a half-life of 43.0

A radioactive isotope has a half-life of 43.0 min. At t = 0 its activity is 0.376 Ci. What is its activity at t = 2.00 h?

Q: The radioactive nuclide 199Pt has a half-life of 30.

The radioactive nuclide 199Pt has a half-life of 30.8 minutes. A sample is prepared that has an initial activity of 7.56 * 1011 Bq. a. How many 199Pt nuclei are initially present in the sample? b. H...

Q: Hydrogen atoms are placed in an external magnetic field. The protons

Hydrogen atoms are placed in an external magnetic field. The protons can make transitions between states in which the nuclear spin component is parallel and antiparallel to the field by absorbing or e...

Q: At an archeological site, a sample from timbers containing 500 g

At an archeological site, a sample from timbers containing 500 g of carbon provides 2690 decays>min. What is the age of the sample?

Q: a. If a chest x ray delivers 0.25 mSv

a. If a chest x ray delivers 0.25 mSv to 5.0 kg of tissue, how many total joules of energy does this tissue receive? b. Natural radiation and cosmic rays deliver about 0.10 mSv per year at sea level....

Q: If a person’s entire body is exposed to 5.0 J

If a person’s entire body is exposed to 5.0 J / kg of x rays, death usually follows within a few days. a. Express this lethal radiation dose in Gy, rad, Sv, and rem. b. How much total energy does a...