Radioactivity Flashcards
Mass number
Total number of protons + neutrons
Isotope
Atoms with the same number of protons but a different number of neutrons
How much does the mass number and atomic number decrease in Alpha radiation
Mass number= -4
Atomic n umber= -2
What is beta radiation
When a neutron turns into a proton and an electron is emitted
Mass number stays the same, but proton number (atomic) goes up by 1.
What is an ion
Ions are charged particles
Which radioactive source is most ionising?
Alpha particles
Which radioactive source is least ionising?
Gamma rays
What happens when alpha particles enter your body?
If alpha enters your body it can cause mutations to cells and cause cancer as it is very ionising
How far does Alpha travel and how is it stopped?
Alpha travels very few cms and can be stopped by air, paper or even skin
Rank Alpha, Beta and Gamma Lowest to highest based on penetration power
-Alpha
-Beta
-Gamma
How do you stop Gamma rays?
With thick lead or very thick concrete
How do you stop Beta particles?
By using Aluminium
What are the uses of Radioactive particles?
-Alpha is used in Smoke Alarms
-Beta is used to make Aluminum or paper the right thickness
What is background radiation
Radiation that is always occurring from natural or man-made sources in the surroundings.
Radioactive decay is a ….. Process
Random
Give examples of both natural and man-made sources of background radiation
Natural:
-Soil and air
-Cosmic rays from space (The sun)
-Living organisms
Man-made:
-Nuclear waste
-Fallout from Nuclear disasters.
Differences between alpha and beta radiation
-Alpha radiation has a higher mass than Beta radiation
-Alpha radiation is more ionising than beta radiation
Why can radon gas be harmful to humans
-Radon is a gas meaning it can easily be inhaled
-Radon gas contains alpha particles which when inside the body can cause both irradiation and contamination of internal organs
-Alpha is highly ionising
Why can Thorium (Solid) be harmful to humans
-Thorium contains alpha particles which are highly ionising
-However it is a solid meaning it is difficult to enter the body, meaning Thorium can only cause irradiation
-Harm is only caused when inside the body as Alpha particles are stopped by a few cm of air.
How to measure count rate from radioactive source and take into account background radiation
-Measure count rate without radioactive source present
-Measure the background radiation multiple times and calculate mean
-Measure the count rate with radioactive source in room
-Subtract background radiation from count rate with radioactive source.
What type of radiation isn’t stopped by lead
Gamma
