The binding energy of a nucleus is 369.4 MeV. What is the mass defect of the nucleus in atomic mass units?

A radioactive sample studied in a lab is found to have a half-life of 25 hours. If the initial sample contained 7.5x10¹⁰ radioactive nuclides estimate the number of radioactive nuclides present in the sample after 10 hours.

A living specimen in equilibrium with the atmosphere contains one atom of 14C (half-life = 5 730 yr) for every 7.7 × 1011 stable carbon atoms. An archeological sample of wood (cellulose, C12H22O11) contains 21.0 mg of carbon. When the sample is placed inside a shielded beta counter, 837 counts are accumulated in one week. Assuming that the cosmic-ray flux and the Earth’s atmosphere have not changed appreciably since the sample was formed, find the age of the sample. ( Atomic mass of C is 12u)

A radioactive sample with a half-life of 5.3 weeks has 1.04e+15 nuclides present in the initial sample. a) What is the initial activity of this sample? Bq b) How many days does it take for this sample to decay to 3.09e+14 nuclides? days

Plutonium-239 (atomic number 94) is a by-product of nuclear power plants. It decays via alpha and gamma decay. The half-life for the decay is 24100 years. What is the decay constant for Pu-239 expressed in inverse years and inverse seconds? If the sample of Pu-is measured to have an activity of 150 decays per second today, how many years would it take for the sample to reduce to an activity of 5 decays per second? How many Pu-239 nuclei are in the sample measured today?

the decay of a radioactive material has a count rate is 2000 decays/min.  4 hours later, the decay rate is 500 counts/min.  what is the half-life?

A sample of radioactive material has a half-life of 12 hours. If the initial sample contained 6.2x10¹3 radioactive nuclides estimate the number of radioactive nuclides present in the sample after 5 hours.

(a) At an initial time, a radioactive sample has an activity of 8.77x104 Bq. After 3.88 hours the activity is 5.35x104 Bq. (A) What is the half-life of the isotope? (B) What is the activity after an additional 3.88 hours? (A) (in s) OA: 6.426x103 OB: 9.317x103 oC: 1.351x104 OD: 1.959x104 OE: 2.840x104 OF: 4.119x104 OG: 5.972x104 (B) (in Bq) H: 8.660x104 OA: 1.387x104 OB: 1.845x104 OC: 2.454x104 OD: 3.264x104 OE: 4.341x104 OF: 5.773x104 OG: 7.678x104 OH: 1.021x105

help please

Calculate the binding energy of the last neutron in the 40K nucleus.   Eb = _____ MeV