Atomic and Nuclear Physics Answers

A 145 gram sample of a certain radioactive isotopes had a half-life of 500 years. If 4 half-lives go by, how much of the original isotope is left?

Electricity costs $0.10 per kilowatt-hour. How does it cost a family each year if they use 250 kilowatt-hours per month?

Yogi Bear’s class of 18 students used 270 kilowatt-hours of energy last week. What is the per capita energy usage in kilowatt-hours?

A sample of thallium-208 has a half-life of 3.053 minutes. What fraction of the parent material will remain after 12.212 minutes?

A 200 N net force acts on a 50 kg box. What is the acceleration of the box?

When a thin foil is bombarded with a particles, a few of them are scattered back toward the source. Rutherford concluded from this that the positive charge of the atom—and also most of its mass—must be concentrated in a very small “nucleus” within the atom. What was his line of reasoning?

How is the energy of a photon dependent on the frequency and wavelength? Based on that, how many photons are emitted in a nitrogen gas laser pulse with a wavelength of 337 nm and energy of 3.83 mJ?

why charged particles with very low incident energies only elastically scatter