Question 1

Tellurium-125 (¹²⁵Te) has:

Accepted Answer

The atomic number of tellurium is 52, meaning it has 52 protons. To find the number of neutrons in ¹²⁵Te, we subtract the atomic number from the mass number: 
125 - 52 = 73 
Therefore, ¹²⁵Te has 52 protons and 73 neutrons, making choice C the correct answer.

Question 2

Radioactive material that is attached to or associated with dust particles or in liquid form on various surfaces defines the term:

Accepted Answer

Radioactive material that is attached to or associated with dust particles or in liquid form on various surfaces is referred to as radioactive contamination.

Question 3

The actual long-term health effects of a "dirty bomb" are likely to be:

Accepted Answer

The actual long-term health effects of a "dirty bomb" are expected to be minimal compared to a nuclear explosion. A dirty bomb is designed to spread radioactive material over a limited area, whereas a nuclear explosion produces far more radioactive fallout that can spread over a wider area and have devastating long-term health effects. While a dirty bomb can still cause local contamination and potential health risks, the overall impact is not expected to be catastrophic or maximal.

Question 4

What is the half-life of Technetium-99m?

Accepted Answer

The half-life of Technetium-99m is approximately 6 hours, making it suitable for medical imaging due to its relatively short half-life, which minimizes radiation exposure.

Question 5

During a radiation emergency,the dose limit for individuals engaging in lifesaving activities is:

Accepted Answer

The dose limit for individuals engaging in lifesaving activities during a radiation emergency is 250 mSv per event. This higher limit recognizes the critical nature of their tasks and the importance of saving lives, even at the risk of higher radiation exposure.

Question 6

While a patient receiving Iodine-131 (¹³¹I) therapy is hospitalized,a large,_________,rolling lead shield can be positioned between the patient and any attending personnel for protection.

Accepted Answer

A lead shield up to 1-inch-thick is typically sufficient for protection against the gamma radiation emitted by Iodine-131, balancing effectiveness and practicality.

Question 7

If enough explosives are used to spread radioactive material over a broad area,then radioactivity is:

Accepted Answer

The answer of If enough explosives are used to spread...

Question 8

Therapeutic radioisotopes are characterized by:

Accepted Answer

Therapeutic radioisotopes have relatively long half-lives, usually between a few days and a few weeks. This allows them to remain in the body long enough to penetrate and target cancer cells, but not long enough to cause significant damage to healthy cells. Short half-lives would make them less effective for therapeutic purposes, while constant half-lives that last for eternity do not exist in nature.

Question 9

Each Fluorine-18 (¹⁸F) nuclear transformation by positron decay yields two highly penetrating _________ photons.

Accepted Answer

Fluorine-18 (¹⁸F) nuclear transformation by positron decay yields two photons with an energy of 511-keV, which are highly penetrating.

Question 10

Diagnostic techniques in nuclear medicine typically make use of ___________ radioisotopes as radioactive tracers.

Accepted Answer

Short-lived radioisotopes are ideal for diagnostic techniques in nuclear medicine as they emit radiation for a short period, reducing the risk of long-term exposure and potential harm to the patient. Additionally, short-lived isotopes decay quickly, which means they can be used for diagnostic imaging without any long-term storage requirements.

Question 11

The design of a _______________ imaging suite involves significant radiation safety concerns.

Accepted Answer

The answer of The design of a _______________ imaging suite...

Question 12

During a radiation emergency,at a dose rate of ____________,emergency personnel should await specific instructions from radiation experts on how to proceed.

Accepted Answer

A dose rate of 0.1 Sv/hr is considered a high dose rate and emergency personnel should await specific instructions from radiation experts on how to proceed.

Question 13

In __________,a neutron transforms itself into a combination of a proton and an energetic electron.

Accepted Answer

This process is known as beta decay, in which a neutron in the nucleus decomposes into a proton, an electron (known as a beta particle), and an antineutrino.

Question 14

Considering the design of the medical imaging suites listed below,which suite presents the most unique additional radiation safety problems?

Accepted Answer

PET and CT imaging suites present the most unique additional radiation safety problems due to the higher radiation doses used, the longer scan times, and the need for radiation shielding to prevent exposure to the staff and the public. PET scans use a radioactive tracer that emits positrons, which are picked up by detectors and used to create an image of the body. CT scans use ionizing radiation to create detailed images of the body's internal structures. Both PET and CT require careful planning and monitoring to minimize radiation exposure to patients and staff.

Question 15

Iodine-125 (¹²⁵I) in the form of titanium-encapsulated cylindrical seeds has been used quite extensively within the past decade to give a tumoricidal radiation equivalent dose for:

Accepted Answer

Iodine-125 seeds are commonly used for internal radiation therapy for prostate cancer that has not spread outside of the prostate gland. The seeds are implanted directly into the prostate tissue, allowing for localized radiation therapy. Iodine-125 is a low-energy radioisotope that emits a type of radiation called gamma rays, which can penetrate only a short distance into tissue. This means that the radiation mostly affects the cells near the seeds and does less damage to surrounding healthy tissue.

Quiz 14: Radioisotopes and Radiation Protection