Multiple choice problems in Nuclear reactions.

1. To make nuclear fission more efficient, which device is used in a nuclear reactor to slow the speed of neutrons?
i.internal shield
ii.external shield
iii.control rod
iv.moderator
v.none of the above

2. In nuclear reactions:
a.small amounts of mass are converted to a large amount of energy
b.mass and energy are destroyed
c.large amount of energy are converted to small amount of mass
d.small amount of mass are converted to large amounts of mass
e.None of the above

3. Which radioactive emanations have a charge of -1?
A.neutrons
B.gamma rays
C.alpha particles
D.beta particles
E.none of the above

4. Which sample will decay least over a period of 30 days?
A.10 g of Au-198
B.10 g of I-131
C.10 g of P-32
D.10 g of Rn-222
E.cannot be determined

5. Which nuclide is a radioisotope used in the study of organic reaction mechanisms?
i.carbon-12
ii.carbon-13
iii.carbon-14
iv.uranium-235
v.uranium-238

6. Complete the equation 82Pb211 à -1e0 + ¬¬¬¬¬_______ by writing the symbol of the missing particle:
A.81Tl211
B.83Bi211
C.82Pb210
D.82Pb211 +
E. none of the above

7. Plutonium-242 decays via alpha emission, which equation represents this balanced nuclear equation?
A.94Pu242 à 2He4 + 92U236
B.94Pu242 à 2He4 + 92U238
C.94Pu242 à 1n0 + 92U238
D.94Pu242 à 2He4 + 92Pb238
E. none of the above

8. Complete the nuclear equation 73Ta177 electron capture à by writing the symbol of the missing particle:
A.74W177
B.74W178
C.72Hf177
D.72Hf178
E. none of the above