Question

please help with parts in case 1 and case 2! thanks you!

Correct (100,0%) submit Find its decay constant in write the result in terms of 10 Keep 4 decimal places. 1.2327 Correct (100.046) Submit x10-7-1 Case 1: The mass of the initial radioactive sample is 6.20 kg. Some time after the initial sample was prepared, it was found that 0.447 kg radioactive materials has decayed. (h) What is the mass in kg) of the radioactive material that remains in the sample ? Keep 3 decimal places. Enter a number ke Submk (5 attempts remaining Find the time (in days) for this case. Keep 2 decimal places. Enter a number days Submit is attempts remaining Case 2: Another sample x100 (c) To have an initial activity of 10397.38 decays/s (Bq), how many radioactive nuclei does the initial sample contain? Write the result in terms of 1010. Keep 2 decimal places. Enter a number Submit (5 attempts remaining (d) What is the activity in decays/s (Bq) after 7.00 days! Keep 2 2 decimal places. Ented a number decaya/s (R) Submit (attempts remaining) (e) How long In days, from the initial time) does it take for the activity to reach 8622.72 decays/s (Bq)? Keep 2 decimal places Enter a number days Submit (5 attempts remaining)

Answer 1

Case 1 The mass remains of radioactive sample that (6•20 – 0.447) 5.753 kg in the Sample is the is 7 According to radioactive law, no. of nuclei present after time t tre cos half life No 2 6:20 tro 2 5.753 t/c or 2 11 10777 1:08 ON 119 th 2. - 2 ta tha a 01 ela 64.8 9 07 t 7.2 day case Initial activity Ao - No A. ΟΥ, 10 39.7338 0.693 2 93/464-8X24X360) No = 8,4 xlolo → After 7 days, radioactive nuclei present 8.4x100 7.794 X10'' No Na 2 tle 7164.8 2 activity Ac 0.693 64.8 X 24X3600 x 7.794 yiolo A 9647.28 decays/ see,