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
5 Responses
You go for your extra credit, but you can at least study for it.
huh
1. Nuclear reaction.
2. Helium.
3. Pu.
4. Cadnium.
5. Plutonium.
6. Involve changes in the nucleus.
7. Americium and Curium.
8. Atomic weights.
9. Energy.
10. Nucleus.
11. Moderators.
12. Cadnium.
13. Remains the same.
14. Increases.
15. Increases.
16. Decreases.
17. Remains the same.
18. Decreases.
19. Remains the same.
20. Increases.
Ashley, you’re new. A few pointers about this part of the computer world.
We are not here to do all your homework.
You could have spent the time to put all these questions on-line looking up answers in your text.
Putting multiple choice questions just verifies the above statements. If you provided answers, we could check them.
1] Nuclear reaction
2] Helium
3] 94Pu239
4] cadmium though cadmium is very toxic
5] Plutonium
6] involve changes in the nucleus
7] americium and curium
8] atomic weights
9] energy
10] Nucleus
11] Moderator
12]
13] Stays the same
14] increases; a neutron has turned into a proton, an electron [ejected] and a neutrino [also ejected]
15]
16] Decrease
17] Decreases but ever so slightly – an electron weighs 1/1836 what a proton weighs
18] When uranium 238 [92 protons, 146 neutrons] changes into plutonium in an atomic reactor, the number of neutrons in atomic nuclei…
Now this one is tricky; what plutonium [94 protons] isotope are they making ? There are more than one !
If Pu239, it will have 145 neutrons, LESS
if Pu 240, 146, THE SAME
Pu 242, 148, more
Pu 244, 150, more
“19: During fission of uranium 235 in an atomic bomb, the number of neutrons ______________.
increases
decreases
remains the same
Answer 4”
Not sure what the “answer 4” means….
you can tell for sure by finding out what the fission products are. Some free neutrons are emitted. Also, what the U235 splits into is not always the same.
20] For the Sun, increases.
However, I will note that in some stars, once they have fused all their hydrogen to helium, they shrink, get hotter, then start fusing helium to heavier elements [I *think* Carbon], so the number of helium atoms actually decreases in them.