Question :
41) One symptom of mild radiation sickness is
A) a lowered : 1324826
41) One symptom of mild radiation sickness is
A) a lowered white cell count.
B) a raised white cell count.
C) a lowered red blood cell count.
D) a raised red blood cell count.
E) a white cell count of zero.
42) Sodium-24 has a half-life of 15 hours. How many hours is three half-lives?
A) 60 hours
B) 45 hours
C) 30 hours
D) 15 hours
E) 7.5 hours
43) The half-life of a radioisotope is
A) one-half of the time it takes for the radioisotope to completely decay to a nonradioactive isotope.
B) the time it takes for the radioisotope to become an isotope with one-half of the atomic weight of the original radioisotope.
C) the time it takes for the radioisotope to become an isotope with one-half the atomic number of the original radioisotope.
D) the time it takes for the radioisotope to lose one-half of its neutrons.
E) the time it takes for one-half of the sample to decay.
44) Iodine-123, which is used for diagnostic imaging in the thyroid, has a half-life of 13 hours. If 50.0 mg of I-123 were prepared at 8:00 a.m. on Monday, how many mg remain at 10:00 a.m. on the following day?
A) 50.0 mg
B) 25.0 mg
C) 12.5 mg
D) 6.25 mg
E) 3.13 mg
45) A wooden object from a prehistoric site has a carbon-14 activity of 10 counts per minute (cpm) compared to 40 cpm for new wood. If carbon-14 has a half-life of 5730 years, what is the age of the wood?
A) 1430 yr
B) 5730 yr
C) 11,500 yr
D) 17,200 yr
E) 22,900 yr
46) Krypton-79 has a half-life of 35 hours. How many half-lives have passed after 105 hours?
A) 1 half-life
B) 2 half-lives
C) 3 half-lives
D) 4 half-lives
E) 5 half-lives
47) The half-life of bromine-74 is 25 min. How much of a 4.0 mg sample is still active after 75 min?
A) 0.50 mg
B) 1.0 mg
C) 2.0 mg
D) 0.25 mg
E) 4.0 mg
48) An imaging technique in which a computer monitors the degree of absorption of X-ray beams is known as
A) positron emission tomography (PET).
B) magnetic resonance imaging (MRI).
C) computerized tomography (CT).
D) radioactive iodine uptake (RAIU).
E) a scan.
49) An imaging technique that detects the energy emitted by hydrogen atoms in a magnetic field is known as
A) positron emission tomography (PET).
B) computerized tomography (CT).
C) magnetic resonance imaging (MRI).
D) radioactive tracer study.
E) supermagnetic tomography (SMT).
50) The most widely used medical isotope in nuclear medicine is
A) Tc-99m.
B) I-131.
C) P-32.
D) I-125.
E) Co-60.
51) The dosage of technetium-99m for myocardial imaging is 280 μCi/kg of body weight. How many mCi should be given to a patient weighing 65 kg? (1 mCi = 1000 μCi)
A) 0.0043 mCi
B) 4.3 mCi
C) 18 mCi
D) 230 mCi
E) 1.8 × 104 mCi
52) A patient receives 3.0 mL of a solution containing technetium-99m for a breast image. If the activity of the technetium-99m is 9.5 mCi/mL, what is the dose received by the patient?
A) 3.2 mCi
B) 29 mCi
C) 320 μCi
D) 9.5 mCi
E) 28.5 mCi
53) When an atom of uranium-235 is bombarded with neutrons, it splits into smaller nuclei and produces a great amount of energy. This nuclear process is called
A) fission.
B) fusion.
C) decomposition.
D) chain reaction.
E) ionization.
54) In the Sun, nuclei of hydrogen combine to form a larger nucleus and release a great amount of energy. The process is known as
A) fission.
B) fusion.
C) metathesis.
D) chain reaction.
E) ionization.
