Name ____________________________
Binding energy Practice II
1. One of the common fusion processes used in thermonuclear weapons is the fusion of two Hydrogen-2 atoms
(known as Deuterium atoms) to form a single atom and a neutron.
A. Write a balanced nuclear equation for the fusion reaction described above.
B. Calculate the total binding energy of a Hydrogen-2 atom. The observed mass of a H-2 atom is 2.01410178
amu.
C. The fusion reaction described requires two Deuterium atoms to join together. What is the total binding energy
of the two deuterium atoms?
D. Calculate the total binding energy of the atom that forms from this reaction. It’s observed mass is 3.0160293
amu.
E. Which nuclei is more stable, the deuterium or the atom formed from the fusion? How do you know?
F. What is the total change in binding energy from the two deuterium atoms to the
single atom formed in the fusion. Is this energy released or absorbed during the nuclear reaction.
G. The total change in energy calculated in part F is a relatively small amount of energy, but that is the energy
released when only two atoms of H-2 fuse. When a sample of just 2.0 grams of H-2 fuse, approximately 6.0 x
1023 atoms are available to fuse. If all of these available atoms fused, calculate the joules of energy that would
be involved in the reaction.
H. Most nuclear reactions are far from 100% efficient. If only 25% of the atoms available in part G fused, how
much energy would be involved in the reaction?
2. In one common nuclear process used in nuclear power plants a Uranium 235 nucleus is shot with a high speed
neutron to form a Krypton (Kr)-91 atom, a Barium (Ba) -142 atom and three other identical particles.
A. Write a balanced nuclear equation for this reaction.
B. Is the reaction described a fission or a fusion reaction? How can you tell? Is it spontaneous or man-made
reaction? How can you tell?
C. Look at the self-sustaining chain-reaction nuclear reaction described in section 24-3 of your textbook. What
happens to the three identical particles that are produced in the reaction described above?
D. What is a control rod? How is one used to try to control a self-sustaining chain reaction nuclear reaction like
the one described above?
E. Calculate the binding energy per nucleon of Uranium-235. Its observed mass is 235.0439299 amu.
F. Calculate the binding energy per nucleon of Krypton-91. Its observed mass is 90.9234424 amu.
G. Calculate the binding energy per nucleon of Barium-142 which has an observed mass of 141.916453 amu.
H. Does the described reaction create more or less stable particles than it started with? How can you tell? Is
energy released or absorbed during the reaction? How can you tell?
I.
Calculate the total change in binding energy during the reaction of one Uranium atom transmutating into a
Barium atom and a Krypton atom as described.
J.
A fuel cell in a nuclear reactor can contain as many as 1 x 1027 atoms of uranium 235. If all of these atoms
were to undergo the reaction described above, how many Joules of energy could be produced?
K. It takes about 2.2 pounds of coal to produce approximately 32 million joules of energy. How many pounds of
coal would be needed to provide the same amount of energy as the Uranium described in question J?