Radiation Physics and Fundamentals Flashcards
7 cards from real RSO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Radiation Physics and Fundamentals flashcards as text
Which type of radiation has the greatest ionizing power but the least penetrating ability?
Answer: Alpha particles
Alpha particles are highly ionizing due to their large mass and double positive charge, but they are stopped by a few centimeters of air or a sheet of paper.
The SI unit of radioactivity is the Becquerel (Bq). One Becquerel is defined as:
Answer: One disintegration per second
One Becquerel equals one nuclear disintegration (decay event) per second.
Which of the following best describes gamma radiation?
Answer: High-energy electromagnetic radiation
Gamma radiation consists of high-energy photons (electromagnetic radiation) emitted from the nucleus during radioactive decay.
The half-life of a radioactive isotope is the time required for:
Answer: The activity to decrease to half its original value
Half-life is the time for the activity (number of decays per unit time) of a radioactive sample to decrease to half its initial value.
Which nuclear process results in the emission of a positron (β+)?
Answer: Beta-plus decay
Beta-plus decay occurs when a proton converts to a neutron inside the nucleus, emitting a positron and a neutrino.
An RSO is working with a source of I-131, which has a half-life of approximately 8 days. If the initial activity is 40 mCi, what will the activity be after 24 days?
Answer: 5 mCi
24 days equals 3 half-lives (24/8 = 3), so the activity decreases by half three times: 40 → 20 → 10 → 5 mCi.
Which statement correctly describes the relationship between photon energy and penetrating ability for X-rays and gamma rays?
Answer: Higher-energy photons are more penetrating
Higher photon energies correspond to greater penetrating ability because higher-energy photons are less likely to interact per unit path length through matter.