Radioactivity, uses and dangers Flashcards
What can the activity of a radioactive source be defined as?
The rate at which the unstable nuclei decay
What unit is activity measured in?
Becquerels
How does activity vary with time?
The activity of a radioactive source decreases over time
How do smoke detectors use radiation?
-Smoke detectors use Alpha radiation
-The alpha radiation ionizes air within the detector, creating a current
-The alpha emitter will be blocked when smoke enters
-the alarm is triggered by a microchip that detects when the sensor no longer detects alpha radiation
How can you measure thickness using radiation?
-You will use Beta radiation to detect thickness, with the amount of beta radiation penetrating being monitored using a detector
-The thicker the material, the lower the count rate would be
-The thinner the material, the higher the count rate would be
How can you treat cancer using radiation?
-Radiation can both cause and kill cancer
-Ionising radiation can kill living cells
-Gamma rays are used as they can penetrate the body and reach the tumor
-The rays are aimed towards the tumor to minimise damadge to nearby healthy tissue
Why is Gamma well suited to sterilizing medical equipment?
-It has the highest penetrating power out of all the other types of radiation
-It is penetrating enough to expose all sides of the instruments
-Instruments can be sterilized without removing the packaging
What is Irradiation?
When an object is exposed to a source of radiation but does not become radioactive
What is contamination?
When an object becomes radioactive due to the presence of a source of radiation
How can you prevent Irradiation?
-Blocking by using shielding such as lead
-Monitoring the persons exposure to radiation
How can you prevent contamination?
Radiation cannot be blocked once an object is contaminated, but can be prevented by handling the source safely e.g using tongs or wearing protective clothing
What could cause Irradiation?
Deliberate exposure to radiation
What could cause contamination?
Accidental transfer of radioactive material
What types of radiation are the most dangerous when OUTSIDE the body? Why?
High penetrating radiation are able to pass through skin and reach the living cells within the body
What types of radiation are the most dangerous when INSIDE the body? Why?
High ionizing radiation are most likely to cause the most harm to cells within the body
What are the dangers of ionising radiation?
-Damage living cells and tissues
-Cause mutations that can lead to cancer by breaking DNA
What containers are Alpha radiation stored in?
Stored in plastic or metal containers
What containers are Beta radiation stored in?
Stored in Metal canisters or concrete silos
What containers are Gamma radiation stored in?
Lead lined, thick concrete silos
