Find the activity A of a sample containing 4E-6 g of 60/27 Co (T1/2= 5.27 years). (Use 59.93 u as the mass of 60/27 Co.)  Number of 60/27Co nuclei: A)4.02E16 B)9.03E33 C)9.03E36 D)4.02E19  Radioactive decay constant: A)2.41E8 B)0.132 C)4.15E-9 D)7.60     Given A(t)=A0exp⁡(−λt), what are the units of the radioactive decay constant? A)sec/decay B)kg/decay C)decays/sec D)decays/kg

Potassium-argon dating is used to measure the age of rocks formed from cooled lava by determining the fraction of the original 40K remaining in a sample from the ratio of 40K:40Ar. Unusually, potassium-40 decays into both 40Ca (89.1% of the time) and 40Ar (10.9% of the time) with a half-life of 1:248 x 10^9 years. 1. Write out balanced nuclear equations for these two decay processes. 2. Calculate the specific activity of 40K.

Please have computer typed.

1) If the activity of a purely radioactive sample of 55Fe is measured to be 0.5 mCi. What is the number of nuclei of this isotope present after 5.4 years. 2) 226Ra (t₁/2 = 1600 y) alpha decays to the 1st excited state of nucleus X with branching ratio 6% and alpha decays to the ground state of X with branching ratio 94%. Calculate the partial half-life for the first mode transition (the one to the first excited state of X). 3) Fill the missing and decide the type of decay in the following decays: a) Co* → [ ] + Co b) ¹50 [ ] + [ ] + ¹5N 40 c) 10K + [ ] 18Ar d) 21 Po 84 e) ¹3 Be →>> 2a + [ ] ¹2Be + [ ]

The half-life of 1311 is 8.04 days. (a) Convert the half-life to seconds. S (b) Calculate the decay constant for this isotope. S-1 (c) Convert 0.570 μCi to the SI unit the becquerel. Bq (d) Find the number of 13¹1 nuclei necessary to produce a sample with an activity of 0.570 μCi. 1311 nuclei (e) Suppose the activity of a certain 13¹1 sample is 6.90 mCi at a given time. Find the number of half-lives the sample goes through in 40.2 d and the activity at the end of that period. (Enter your answer for the number of half-lives to at least one decimal place.) half-lives mCi

A piece of charcoal used for cooking is found at the remains of an ancient campsite. A 1.19 kg sample of carbon from the wood has an activity of 2340 decays per minute. Find the age of the charcoal. Living mate- rial has an activity of 15 decays/minute per gram of carbon present and the half-life of 14C is 5730 y. Answer in units of y.

Both 1)Given a half-life of a radioactive source is 435 years. Calculate the time taken for its activity to reduce from 4.5 Ci to 0.14 Ci? 2) Equation shows nuclear reaction of gamma radiation which incident on an isotope helium. Calculate the energy of the gamma ray in MeV unit? (Given mass of Helium = 3.016029 u, mass of proton = 1.007276 u and mass of neutron = 1.008665 u) 23??+?→211?+01?