Chapter 5 Flashcards
What is the role of a radiation technologist in a hospital or imaging center?
They work where nuclear medicine is used to diagnose and treat various medical conditions.
What protective equipment does a person working with radioisotopes in a nuclear pharmacy wear?
Protective clothing and gloves; they also use a lead glass shield on a syringe.
What types of radiation are described in the learning goal?
Alpha, beta, positron, and gamma radiation.
What causes radioactivity?
It comes from unstable nuclei found in certain elements, which emit radiation to become more stable.
Define a radioisotope.
A radioisotope is an isotope of an element that emits radiation.
What is the atomic symbol and mass number of iodine-131?
The atomic symbol is 1 and the mass number is 131.
List the types of radiation emitted by radioisotopes.
Alpha particles, beta particles, positrons, and gamma rays.
What is ionizing radiation?
Ionizing radiation strikes molecules and knocks away electrons, forming unstable ions.
What are the biological effects of radiation on cells?
It damages the cells sensitive to radiation, causing undesirable chemical reactions and potentially cancer.
What is required for radiation protection against alpha particles?
Paper and clothing.
What materials are needed to block beta particles?
A lab coat or gloves.
What can block gamma rays effectively?
Dense shielding such as lead or concrete.
What methods can limit exposure to radioactive sources?
Minimize time spent near the source and increase distance from the source.
What happens in the nuclear equation for alpha decay?
The mass number of the new nucleus decreases by 4 and its atomic number decreases by 2.
What signifies the mass number and atomic number in radioactive decay?
The sum of mass numbers and atomic numbers must be equal for reactants and products.
What occurs during alpha decay?
A radioactive nucleus emits an alpha particle.
In beta decay, how does the mass number and atomic number change?
The mass number remains the same and the atomic number increases by 1.
What is positron emission?
A process where a proton is converted to a neutron and a positron, decreasing the atomic number by 1.
What is gamma radiation?
Energy emitted from an unstable nucleus without changing mass or atomic number.
What are radioactive isotopes produced through?
They are produced when a stable nucleus is converted to a radioactive one by bombardment with particles.
How do you write a balanced nuclear equation for bombardment?
Determine missing mass and atomic numbers based on the reaction.
What is the purpose of a Geiger counter?
To detect alpha particles, beta particles, and gamma rays.
What is the FDA’s requirement about irradiated foods?
It requires a symbol to appear on the packaging.
What is the main function of dosimeters?
To detect the amount of radiation exposure from X-rays, gamma rays, and beta particles.
How does average annual radiation exposure occur?
From naturally occurring radioisotopes in buildings, food, water, and air.
What is the definition of half-life?
The time for the radiation level to decrease to half of the original value.
What can be determined using carbon-14?
The age of archaeological finds like the Dead Sea Scrolls.
How does one calculate the remaining amount of a radioisotope after several half-lives?
By repeatedly halving the initial quantity.
What fraction of the half-life of carbon-14 has passed if the Dead Sea Scrolls are 2000 years old?
2000 years is a fraction of 5730 years, the half-life of carbon-14.
After how much time does a 64 mg sample of 1-123 reduce to 8 mg?
After 39 hours, equivalent to 3 half-lives.
