Question

section 24.3 nuclear reactions
in your textbook, read about the process of induced nuclear transmutation.
for each statement below, write true or false.

1. transmutation is the conversion of an atom of one element to an atom of another element.
2. all nuclear reactions involve some type of nuclear transmutation.
3. scientists induce transmutations by bombarding stable nuclei with high - energy alpha, beta, or gamma radiation.
4. the first induced nuclear transmutation was carried out by marie and pierre curie in 1897.
5. most induced transmutation reactions are produced in high - energy particle accelerators.
6. neptunium and plutonium were the first transuranium elements discovered.
7. the nuclear formula for a neutron is n.
8. the half - life of a radioisotope is the time it takes for that isotope to decay.
9. a radioisotope that decays very rapidly has a short half - life.
10. radioisotopes with very long half - lives are seldom found in earths crust.
11. temperature is the only factor that affects the half - life of a radioisotope.
12. carbon dating is not used to measure the age of rocks because the half - life of carbon - 14 is too short.
13. after an organism dies, its ratio of carbon - 14 to carbon - 12 and carbon - 13 increases.
14. scientists currently believe that all of the possible transuranium elements have been discovered.
15. when an atom of $_ {52}^{125}te$ is bombarded with protons, the products are $_ {53}^{125}i$ and neutrons.
16. mass number and atomic number are conserved in all nuclear reactions.
17. the mass of a 25.0 g piece of $_ {96}^{238}cm$ (half - life: 2.4 hr) will be reduced to 3.1 g after 7.2 hr.

Explanation:

1. Transmutation is indeed the conversion of one - element atom to another, so it's true.
2. Not all nuclear reactions involve transmutation (e.g., some radioactive decay like gamma decay doesn't change the element), so it's false.
3. Scientists induce transmutations by bombarding stable nuclei with high - energy particles like neutrons, protons, etc., not just alpha, beta, or gamma radiation (gamma is a form of electromagnetic radiation and doesn't directly cause transmutation in the way described), so it's false.
4. The first induced nuclear transmutation was carried out by Rutherford in 1919, not the Curies in 1897, so it's false.
5. Most induced transmutation reactions are produced in high - energy particle accelerators, which is true.
6. Neptunium and plutonium were the first transuranium elements discovered, which is true.
7. The nuclear symbol for a neutron is $_0^1n$, just $n$ is not a complete nuclear formula, so it's false.
8. The half - life of a radioisotope is the time it takes for half of the isotope to decay, not just any decay time, so it's false.
9. A rapidly decaying radioisotope has a short half - life, which is true.
10. Radioisotopes with long half - lives can be found in Earth's crust (e.g., uranium), so it's false.
11. Temperature does not affect the half - life of a radioisotope; half - life is a characteristic property of the isotope related to its nuclear stability, so it's false.
12. Carbon dating is not used to measure the age of rocks because the half - life of carbon - 14 is too short compared to the age of rocks, which is true.
13. After an organism dies, its ratio of carbon - 14 to carbon - 12 and carbon - 13 decreases as carbon - 14 decays, so it's false.
14. Scientists do not believe all possible transuranium elements have been discovered as new elements can be synthesized with advanced techniques, so it's false.
15. When an atom of $_{52}^{125}Te$ is bombarded with protons, the products are $_{53}^{125}I$ and neutrons according to nuclear reaction principles, so it's true.
16. Mass number and atomic number are conserved in all nuclear reactions, which is true.
17. Using the half - life formula $N = N_0(\frac{1}{2})^{\frac{t}{T_{1/2}}}$, where $N_0 = 25.0$ g, $T_{1/2}=2.4$ hr, $t = 7.2$ hr. $\frac{t}{T_{1/2}}=\frac{7.2}{2.4}=3$. So $N = 25.0\times(\frac{1}{2})^3=25.0\times\frac{1}{8}=3.125\approx3.1$ g, so it's true.

Answer:

1. True
2. False
3. False
4. False
5. True
6. True
7. False
8. False
9. True
10. False
11. False
12. True
13. False
14. False
15. True
16. True
17. True