Question

(d) Due to alpha decay, l mole of uranium-238 produces 2.96 106 alpha particles per second. Find the half-life, giving your answer in units of years. [5 marks] (e) The average mass of the atoms in a 0.100 kg block of pure carbon is 12.01 u. A small fraction of the atoms are radioactive, with a decay constant of 3.90 x 10-12s. If the activity of the carbon block is 97.8 Bq, calculate what fraction of the atoms are radioactive (i.e. the number that are radioactive divided by the total number)

Answer 1

d戈 det 23 1チ 693

99x102 13 4. 99 X102