Exam 30: Nuclear Physics

The stability of with respect to alpha,beta-plus,and beta-minus decay is to be determined.The following atomic masses in amu are known: 4.002603 31.973907 35.967081 35.968307 35.967546 The nuclide is

Why do heavy nuclei contain more neutrons than protons?

The first nuclear reaction observed saw an alpha particle (Z = 2)interact with a nitrogen nucleus in air (Z = 7)to produce a proton.The energy of the alpha particle was 55 MeV,enough to enable the nuclei to touch in spite of the Coulomb repulsion.What distance between the centers of the alpha particle and the nitrogen was reached? This determines a nuclear radius for nitrogen.Use 1 fm = 10^-15 m.

In beta-minus decay,the number of protons in a nucleus increases but the number of nucleons does not change.

Scandium ⁴⁴Sc decays by emitting a positron.The nuclide that is the product of the decay is:

Nuclei that are all isotopes of an element all have the same

The half-life of cobalt-60 is 5.3 years,while that of strontium-90 is 28 years.Suppose you have a sample of each,such that they initially contain equal numbers of atoms of these nuclides.How will the activities (number of decays per unit time)of the samples compare?

The half-lives of cobalt-60 and strontium-90 are 5.3 years and 28 years,respectively.Suppose that samples of cobalt-60 and strontium-90 are such that they initially have the same activity.What will be true of the numbers of cobalt-60 and strontium-90 nuclei in these samples?