To make the newly discovered, very large elements of the periodic table, researchers shoot a medium-size nucleus at a large nucleus. Sometimes a projectile nucleus and a target nucleus fuse to form one of the very large elements. In such a fusion, is the mass of the product greater than or less than the sum of the masses of the projectile and target nuclei?

The half-life of this nucleus is 1.0 seconds. For the following times fill in the rest of the chart and predict the number of parent nuclei left and the number of new daughter nuclei produced.     Time (seconds) Number of half-lives Parent Nuclei Daughter nuclei 0.0                 Start 100 0 1.0 1 50 50 2.0 2 25 75 3.0 3 12   4.0 4     5.0 5     6.0 6     7.0 7     8.0 8     9.0 9     10 10

A fusion reaction that has been considered as a source of energy is the absorption of a proton by a boron-11 nucleus to produce three alpha particles:                                  1/1H + 11/5B → 3(4/2He)This reaction is an attractive possibility because boron is easily obtained from the Earth’s crust. A disadvantage is that the protons and boron nuclei must have large kinetic energies for the reaction to take place. This requirement contrasts with the initiation of uranium fission by slow neutrons. (a) How much energy is released in each reaction? (b) Why must the reactant particles have high kinetic energies?

As a staff scientist at a nuclear power plant, it is your job to understand radioactive substances used by your co-workers. In a particular radioactive sample, you found that the number of nuclei decreased to one-sixth the original number of nuclei over an 18 d period. Determine the half-life of the sample (in days).

The nuclear radius of a fictitious element is 3.145 fm. The number of protons and the number of neutrons in this nucleus are (select all that apply): 09 and 9 O8 and 10 O9 and 8 O8 and 8 9 and 10 O 10 and 8 O8 and 9 O 10 and 9

b) Complete the following decay reaction by identifying both the temporary nucleus (??) and the end product (?) that it decays into. In this case, sodium-23 is bombarded with protons, forming a short-lived nucleus which quickly undergoes alpha decay. 2Na+H → (??) → (⁄?) + ª Enter the chemical symbol for the temporary nucleus: Enter the mass number for the end product, A = Enter the atomic number for the end product, Z = Enter the chemical symbol for the end product: AV A/ AV 10

(a) The daughter nucleus formed in radioactive decay is often radioactive. Let N10 represent the number of parent nuclei at time t = 0, N1(t) the number of parent nuclei at time t, and λ1 the decay constant of the parent. Suppose the number of daughter nuclei at time t = 0 is zero. Let N2(t)be the number of daughter nuclei at time t and let λ2 be the decay constant of the daughter. Show that N2(t) satisfies the differential equation                            (dN2)/(dt) = λ1N1 - λ2N2(b) Verify by substitution that this differential equation has the solution                            N2(t) = (N10λ1)/(λ1 - λ2)(e-λ2t - e-λ1t)This equation is the law of successive radioactive decays. (c) 218Po decays into 214Pb with a half-life of 3.10 min, and 214Pb decays into 214Bi with a half-life of 26.8 min. On the same axes, plot graphs of N1(t) for 218Po and N2(t) for 214Pb. Let N10 = 1 000 nuclei and choose values of t from 0 to36 min in 2-min intervals. (d) The curve for 214Pb obtained in part…

238U is long-lived but ultimately unstable; it will eventually spontaneously break into two fragments, a 4He nucleus and a 234Th nucleus, in a process called alpha decay, which we’ll learn about in the next section. A great dealof energy is released in the process. What must be true about the masses of the nuclei involved?A. mU > mTh + mHeB. mU = mTh + mHeC. mU < mTh + mHe

Radon is a colorless, odorless, radioactive noble gas. Because it occurs naturally in soil, it can become trapped in homes and buildings. Despite a short half-life of only 3.83 days, high concentrations of radon indoors can pose a risk of lung cancer. (For this reason, many modern homes and buildings have radon reduction systems installed.) Consider an enclosed space in a building which contains 3.03 g of radon gas at time t = 0. What mass of radon (in g) will remain in this space after 2.20 days have passed? |9 Need Help? Read It

What is the activity (in particles/s) of a sample of Carbon-14 that contains 9.070E+21 nuclei?