1: The equation 92U238 + 0n1 –> 92U239 represents
an electronic reaction
a molecular reaction
a nuclear reaction
an oxidation reaction
2: In the hydrogen bomb the fusion of hydrogen isotopes results in the production of
barium
helium
plutonium
proton
3: The atom whose nucleus contains the largest number of neutrons is
92U235
92U239
93Np239
94Pu239
4: Neutrons are best absorbed in an atomic pile by rods of
cadmium
calcium
copper
zinc
5: A man-made element is
gold
plutonium
sodium
zinc
6: Radioactive changes differ from ordinary chemical changes because radioactive changes
are explosive
absorb energy
involve changes in the nucleus
release energy
7: Two man-made elements with atomic numbers greater than 92 are
americium and curium
thorium and actinium
U238 and U239
U235 and U238
8: Isotopes of uranium have different
atomic numbers
atomic weights
numbers of planetary electrons
numbers of protons
9: The Law of Conservation of Mass-Energy states that matter may be converted into __________.
atomic charge
energy
mass
liquid
10: In reactions involving atomic energy changes take place in the _______ of an atom.
proton
valence shell
neutron
nucleus
11: A substance which slows down neutrons so that they may be captured in an atomic pile is known as the __________.
moderator
graphite
slowing rod
inhibitor
12: The rate at which an atomic pile operates is controlled by rods of ______________ or boron steel.
aluminum
boron aluminum
zinc
cadmium
13: As radium is disintegrated, its half-life ____________.
increases
decreases
remains the same
none of the above
14: When a radioactive element undergoes beta disintegration, the atomic number of the nucleus
increases
decreases
remains the same
none of the above
15: As the number of neutrons emitted during a fission reaction increases, the intensity of the fission process __________.
increases
decreases
remains the same
none of the above
16: When a radioactive element undergoes an alpha disintegration, both the atomic weight and the atomic number of the daughter nucleus ___________.
increases
decreases
remains the same
none of the above
17: As bismuth 210 emits electrons, the mass of the daughter nuclei formed ____________.
increases
decreases
remains the same
none of the above
18: When uranium 238 changes into plutonium in an atomic reactor, the number of neutrons in atomic nuclei _____________.
increases
decreases
remains the same
none of the above
19: During fission of uranium 235 in an atomic bomb, the number of neutrons ______________.
increases
decreases
remains the same
Answer 4
20: As fusion occurs in the sun, the number of atoms of helium in the sun _______________.
increases
decreases
remains the same
none of the above
