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.

Answer the following questions about the radiochemistry involved in PET scans. All answers are numerical. (Hint: 1 mCi is exactly 3.7 x 107 Bq. ) a) Fluorine-18 can be synthesized by smashing tritium (3.01605 amu) into 16O (15.99491 amu), which results in the formation of 18F (18.00094 amu) and a neutron (1.00866 amu) according to the this reaction: 3H + 16O → 18F + n How much energy is emitted per mole in this reaction? ________x 10¹¹ J/mol b) If the initial dose of 18F (t1/2 = 109.8 min) received by the patient is 12.00 milliCurie (mCi), what is the disintegration rate (in mCi) in the patient's body at exactly 24 hours after they receive that initial dose? ________x 10-⁹ mCi need both parts or else I will downvote

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 + [ ]

QI/ How much energy is required to remove a neutron from Pd nucleus? using the two methods Where: MAPd)=102.906114u, Ma(Pd)=101.905634u

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

There is more than one isotope of natural uranium. If a researcher isolates 1.00 mg of the relatively scarce 235U and finds this mass to have an activity of 80.0 Bq, what is its half-life in years?

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.

Plutonium-239 (t1₁/₂=2.41X10⁴yr) represents a serious nuclear waste hazard. If seven half-lives are required to reach a tolerable level of radioactivity, how long must ²³⁹Pu be stored?