Page 1681 - College Physics For AP Courses
P. 1681
Answer Key 1669
(b) The greatest known atomic masses are about 260. This result found in (a) is extremely large. (c) The assumed radius is much too large to be reasonable.
82
(a)
(b) Negative energy implies energy input is necessary and the reaction cannot be spontaneous.
(c) Although all conversation laws are obeyed, energy must be supplied, so the assumption of spontaneous decay is incorrect.
Test Prep for AP® Courses
1
(c)
3
(a)
5
When undergoes α decay, it loses 2 neutrons and 2 protons. The resulting nucleus is therefore .
7
During this process, the nucleus emits a particle with -1 charge. In order for the overall charge of the system to remain constant, the charge of the nucleus must therefore increase by +1.
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a. No. Nucleon number is conserved (238 = 234 + 4), but the atomic number or charge is NOT conserved (92 ≠ 88+2).
b. Yes. Nucleon number is conserved (223 = 209 + 14), and atomic number is conserved (88 = 82 + 6).
c. Yes. Nucleon number is conserved (14 = 14), and charge is conserved if the electron’s charge is properly counted (6 = 7 + (-1)).
d. No. Nucleon number is not conserved (24 ≠ 23). The positron released counts as a charge to conserve charge, but it doesn’t count as a nucleon.
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This must be alpha decay since 4 nucleons (2 positive charges) are lost from the parent nucleus. The number remaining is found from:
nuclei
Chapter 32
Problems & Exercises
1
5.701 MeV
3
5
7
(a) 6.958 MeV (b)
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(a) 100 mSv (b) 80 mSv (c) ~30 mSv
