Exam 13: The Atomic Nucleus and Radioactivity

To predict the approximate energy release of either a fission or a fusion reaction, explain how a physicist uses a table of nuclear masses and the equation E = m .

In bombarding atomic nuclei with proton "bullets," the protons must be accelerated to high energies to make contact with the target nuclei

Which of the beams is actually composed of particles?

You are given three radioactive samples (α, β, and γ)and can only dispose of one. The other two you must keep, one in your hand, the other in your pocket. How would you minimize your exposure risk?

Where did the atoms that make up a newborn baby originate?

Complete the following nuclear equation: ?? → At + e

Why might the following nuclear reaction not be very good for energy production in a fission reactor? Fe → Si + Mg + 3 neutrons

How is it possible for an element to decay "forward in the periodic table"--that is, to decay to an element of higher atomic number?

Is it at all possible for a hydrogen nucleus to emit an alpha particle?

The half-life of carbon-14 is 5,730 years. A sample is found to have one-eighth the original amount of carbon-14 in it. How old is the sample?

Which shape is likely to need more material for a critical mass, a cube or a sphere? Why?

A certain radioactive element has a half-life of one hour. If you start with a 1-g sample of the element at noon, how much of this same element will be left at 3:00 PM?

The alpha particle has twice the electric charge of the beta particle but deflects less than the beta in a magnetic field because it

Why might the following nuclear reaction not be very good for energy production in a fission reactor? U → Th + He + 3 neutrons

Which of the following is a major advantage of nuclear-fission-based power plants?

Why is the combination of two protons and two neutrons stable, but two protons and one neutron is not?

The original reactor built in 1942 was just "barely" critical because the natural uranium that was used contained less than 1% of the fissionable isotope U-235 (half life 713 million years). What if, in 1942, the Earth had been 9 billion years old instead of 4.5 billion years old? Would this reactor have reached critical stage with natural uranium? Why?

A pair of protons in an atomic nucleus repel each other, but they are also attracted to each other. Why?

Why are smaller nuclei such as carbon-14 often radioactive? (carbon-12 is the most common and most stable form of carbon.)

What is a half-life?