Atomic and Nuclear Physics Answers

Find the Wronskian of the following functions and determine whether it is linearly dependent or linearly independent on (-∞,∞).

{x2, x+1, x-3} ans, W=8, linearly independent

{3e2x, e2x} ans, W=0, linearly dependent

{x2, x3, x4} ans, W=2x^6, linearly independent

9. Chemical analysis shows that a bone fragment contains 10 g of C. Its activity is 50

counts/min. How old is the bone fragment?

8. A 2.71 g sample of KCl is found to be radioactive. It is decaying at a rate of 4490

Bq. The decay is traced to an isotope of potassium 40K, which constitutes 1.17% of

normal potassium. Calculate the half life of this nuclide.

7. The atomic ratio between Uranium isotope 238U and 234U in a mineral sample is found

to be 1.8 × 104

. The half-life of 234U is 2.5 × 105 yrs. Find the hal-life of 238U.

6. The polonium isotope 210

84 Po is unstable and emits a 5.30 MeV alpha particle. The

atomic mass of 210

84 Po is 20998 and that of 4

2He is 4.0026u. Identify the daughter nuclide

and find its atomic mass in u.

4. How much time is required for 5mg of 22Na (T

1

2 = 2.60 yrs) to reduce to 1 mg?

3. Show that the mass of radium (Mass number= 226, half-life = 1600 yrs) with an

activity of a curie (1Ci) is almost 1gm.

2. One (1) gram of aradioactive substance disintegrates at the rate of 3.7 × 1010 per

second. The atomic weight of the substance is 226. Calculate its mean life.

1. Using the Weiszacker’s formula, calculate the binding energy per nucleon for 235

92 U and

its two fission products: 149

60 Nd and 86

32Ge.

1. Using the Weiszacker’s formula, calculate the binding energy per nucleon for 235

92 U and

its two fission products: 149

60 Nd and 86

32Ge.